Silacyclobutane

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Silacyclobutane
SilacyclobutaneParent.png
SilacyclobutaneBallStick2.png
SilacyclobutaneSpacefilling3.png
Names
Preferred IUPAC name
Siletane
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
  • InChI=1S/C3H8Si/c1-2-4-3-1/h1-4H2
    Key: QZYLHXTXFGOILC-UHFFFAOYSA-N
  • C1C[SiH2]C1
Properties
C3H8Si
Molar mass 72.18
Appearanceclear, colorless liquid
Boiling point 29.8 °C (85.6 °F; 302.9 K)
Vapor pressure 641 mmHg
Related compounds
Related compounds
 Silete; Silolane; Silole; Silabenzene; Phosphetane; Thietane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Silacyclobutane (SCB) or siletane is a four-membered heterocylic ring (silacycle) consisting of one silicon atom and three carbon atoms with the general formula (CH2)3SiH2. Silacyclobutane is one of the simplest molecules in the family of organosilicon compounds. The four-membered ring framework of silacyclobutane is analogous to that of cyclobutane, but one carbon atom is replaced by silicon. All four atoms in silacyclobutane are sp³-hybridized, forming a nonplanar, puckered ring. Derivatives of silacyclobutane are called silacyclobutanes with the general formula (CH2)3SiR2. Since the first synthetic report of silacyclobutane in the 1950s, silacyclobutane and its analogues have garnered considerable attention owing to their high ring strain, Lewis acidity, and tunable silicon-carbon bond activation, which enable diverse ring-opening and ring-expansion pathways. [1] [2]

Contents

Structure

The four carbon atoms in cyclobutane are not coplanar but rather adopt a "puckered" or "butterfly" conformation resulting from the large barrier to internal rotation due to the repulsions of the three adjacent methylene groups. [3] The dihedral angle of the silacyclobutane puckered ring has been calculated as 35.9 ± 2°. [4] For silacyclobutane, the C-Si-C and C-C-C bond angles have been calculated as 78.8° and 100.5°, respectively utilizing multi-configurational self-consistent field (MCSCF). [5]

Puckered/butterfly structure of silacyclobutane. SiletaneStructure2.png
Puckered/butterfly structure of silacyclobutane.

Like cyclobutane, the small heterocyclic ring of silacyclobutane is highly strained, resulting in lower bond energies when compared to related linear or unstrained, silicon-containing or hydrocarbon rings, such as hexane, cyclohexane, or silacyclohexane. Interestingly, the energetic barrier of silacyclobutane [4] (440 cm-1) is lower than that of cyclobutane [6] (498 cm-1), perhaps owing to the greater flexibility of C-Si-C, longer Si–C bonds, and greater bond angle flexibility. Electronic structure calculations of silacyclobutane reveal that the LUMO is lower in energy compared to cyclobutane. [7]

The highly strained nature of silacyclobutanes can be investigated through thermolysis, which can provide insights into ring stability and decomposition. Interestingly, there is a considerable difference in liquid- vs. gas-phase thermal decomposition for these compounds. [8] The liquid-phase pyrolysis of 1,1-dimethyl-1-silacyclobutane with the formula (CH2)3SiMe2 results in ring-opening polymerization at 150-200 °C. [9] In comparison, gas-phase pyrolysis of has been demonstrated to primarily undergo unimolecular decomposition to ethane and dimethylsilene at 400-460 °C. [10] It was later shown that there are two minor decomposition pathways: one that forms methyl radicals via the Si–CH3 bond cleavage and another propene–dimethylsilylene species. [11]

Gas-phase thermolysis products of 1,1-dimethyl-1-silacyclobutane. Thermolysis.png
Gas-phase thermolysis products of 1,1-dimethyl-1-silacyclobutane.

Synthesis and history

Fredrick Stanley Kipping, a pioneer of silicon chemistry in the 1920s was the first to conceptualize silacyclobutane in his series of manuscripts titled "Organic Derivatives of Silicon" [12] [13] and is often credited in its history. However, products formed Kipping's experiments were complex mixtures and he could not conclusively isolate or characterize the silacycles. Kipping's work was one of the earliest demonstrations that silicon could form stable cyclic structures analogous to carbon rings, giving rise to modern organosilicon chemistry.

Grignard reagent addition

In 1954, Sommer and Baum reported the first successful synthesis and isolation of a silacyclobutane, 1,1-dimethyl-1-silacyclobutane. Starting from (3-bromopropyl)trimethylsilane, they formed a disiloxane intermediate and subsequently generated a terminal dihalide that was treated with magnesium metal and dilute diethyl ether to form the respective in situ Grignard reagents, which perform Wurtz-type coupling intramolecular ring closure by preferentially attacking the bromine site first, followed by the chloride site to form a four-membered ring. [14]

Formation of 1,1-dimethyl-1-silacyclobutane from (3-bromopropyl)trimethylsilane treated with acid to form a disiloxane, followed by chlorination to form a dihalide, and Wurtz-type coupling ring closure utilizing Grignard reagents. 1,1-dimethyl-1-silacyclobutane - 2.png
Formation of 1,1-dimethyl-1-silacyclobutane from (3-bromopropyl)trimethylsilane treated with acid to form a disiloxane, followed by chlorination to form a dihalide, and Wurtz-type coupling ring closure utilizing Grignard reagents.

Classically, silacyclobutanes can be formed using Grignard addition. Notably, this method is employed in the formation of benzosilacyclobutanes from a 1-bromo-2-(bromomethyl)benzene starting material by Gilman and Atwell [15] [16] in the 1960s, followed by de Boer et al. [17] and Kang et al. [18] in the 1980s.

Synthesis of benzosilacyclobutanes from 1-bromo-2-(bromomethyl)benzene using Grignard addition reactions. Benzosilacyclobutanes.png
Synthesis of benzosilacyclobutanes from 1-bromo-2-(bromomethyl)benzene using Grignard addition reactions.

Halogenated silacyclobutanes and nucleophilic substitution

Vdovin et al. [19] and Laane et al. [20] in the 1960's synthesized the first halogenated silacyclobutanes, 1,1-dichloro-silacyclobutane and 1,1-difloro-silacyclobutane. The former SiCl2-containing silacyclobutane can be prepared from either (3-bromopropyl)trichlorosilane, which forms more readily, or (3-chloropropyl)trichlorosilane reagents in similar yield. Due to chlorine's nucleophilic properties, 1,1-dichloro-silacyclobutane proves to be a useful intermediate fro accessing further structurally modified silacyclobutanes through nucleophilic substitution. [1] Indeed, as proof of concept, Laane synthesized silacyclobutane-1,1-d2 species using LiAlD4, a deuterated, strong reducing agent analogous to LiAlH4 [20] . In 1980, Auner and Grobe further expanded the collection of known silacyclobutanes through substitution of the SiCl2-containing silacyclobutane using dimethylamine, Grignard reagents, and sodium cyclopentadienide. [21]

Nucleophilic substitution of SiCl2-containing silacyclobutane using dimethylamine, Grignard reagents, sodium cyclopentadienide, and LiAlD4 . SiCl2-silacyclobutane.png
Nucleophilic substitution of SiCl2-containing silacyclobutane using dimethylamine, Grignard reagents, sodium cyclopentadienide, and LiAlD4 .

[2+2] cycloaddition with alkenes

Alternatively, silacyclobutanes can be prepared through [2+2] cycloaddition reaction with alkenes. [1] Jones et al. demonstrate this using in situ formed vinyldimethylchlorosilane, t-BuLi, and 1,3-butadiene to form a mixture of disilacyclobutanes, monosilacyclobutanes, and silicon-containing products (1). [22] [23] When 1,3-butadiene is utilized as a trapping reagent, the reaction is high yielding and E/Z stereochemical products are formed in moderate ratio (2). [24]

[2+2] cycloaddition with alkenes to form silacyclobutanes as a mixture of disilacyclobutanes, monosilacyclobutanes, and silicon-containing products (1) or the E/Z stereochemical products (2) . Cycloaddition silacyclobutane.png
[2+2] cycloaddition with alkenes to form silacyclobutanes as a mixture of disilacyclobutanes, monosilacyclobutanes, and silicon-containing products (1) or the E/Z stereochemical products (2) .

Reactivity

Strain-release Lewis acids

Proposed by Denmark and Sweis in 2002, the term “strain-release Lewis acid” describes the enhanced Lewis acidity of silacyclobutanes that arises from the reduction of ring strain in four-membered ring systems upon coordination by a Lewis base. [2] In silacyclobutane, the ring angle is compressed (79° vs 109° in a typical tetrahedron), which poses significant strain on the molecule. Coordination of a fifth ligand lowers the ring strain due to rehybridization of geometry to a distorted trigonal bipyramid with a silicon center (79° vs 90° in a typical trigonal bipyramidal). [25] This pathway is thermodynamically favored, increasing the tendency of silacyclobutanes to undergo activation by a nucleophile.

Silacylobutane as a "strain-release lewis acid" resulting from favorable coordination of a fifth ligand reducing the ring strain through the formation of a distorted trigonal bipyramidal silicon (79deg vs 90deg typical trigonal bipyramid). SiletaneStrainReleaseLewisAcid.png
Silacylobutane as a "strain-release lewis acid" resulting from favorable coordination of a fifth ligand reducing the ring strain through the formation of a distorted trigonal bipyramidal silicon (79° vs 90° typical trigonal bipyramid).

Pd-catalyzed cross-coupling

Indeed, the enhanced Lewis acidity of silacyclobutanes has been readily explotited in the cross-coupling reaction of alkenyl silacyclobutanes with alkenyl and aryl halides using an activator, such as TBAF, and palladium catalyst to form the cross-coupling products at room temperature in high yield while retaining olefin geometry of the partners (1). [26] Vinyl and propenyl silacyclobutanes can also be useful cross-coupling partners at moderate conditions (2). [27] Further, aryl silacylobutanes can be used as a cross-coupling reagent to form biaryls, although the reaction typically must be refluxed and tri-tert-butyl added to suppress competing homo-coupling (3). [25]

Cross-coupling reaction of alkenyl (1), vinyl/propenyl (2), and aryl silacyclobutanes (3) with alkenyl and aryl halides using an activator and palladium catalyst. SilacyclobutaneCrossCoupling2.png
Cross-coupling reaction of alkenyl (1), vinyl/propenyl (2), and aryl silacyclobutanes (3) with alkenyl and aryl halides using an activator and palladium catalyst.

Transition-Metal-Catalyzed Ring Opening

The strain-release Lewis acidity of silacyclobutanes can be harnessed in tandem with transition-metal-catalysts to facilitate Si-C bond cleavage and ring-opening. These types of reactions have been leveraged to trigger anionic polymerization in many reported syntheses of functional polymers. Qui-Chao et al. go as far to say silacyclobutanes are, "not only building blocks in organic synthesis but also an emerging class of monomers in polymer chemistry." [2]

Palladium and platinum-catalyzed ring opening

In general, palladium and platinum complexes are known to efficiently promote catalytic ring opening of silacyclobutanes. Weyenberg and Nelson extensively demonstrated this in 1964, utilizing platinum metal as a catalyst to hydrosilate a series of silacyclobutanes (1) and showed that the reaction involved exchange of Si-H of the hydrosilane and Si-C of silacyclobutane. [28] They hypothesized that silacyclobutanes might undergo oxidative-addition with platinum to form 1-platina-2-silacyclobutane. A notable palladium-catalyzed ring opening reaction was reported by Tanaka et al. using acid chloride in the presence of triethylamine in mild contains to produce 1-phenyl-4-(chlorodimethylsilyl)-1-butanone in high yield (2). [29] Further, these same researchers observed and deciphered the mechanism behind regioselective ring-opening products being obtained in good yield from silacyclobutanes and aryl iodides with a Pd(PPh3)4 catalyst (3). [30]

Platinum and palladium-catalyzed ring opening reactions with silacyclobutanes. SilacyclobutanePtPdCatalyst.png
Platinum and palladium-catalyzed ring opening reactions with silacyclobutanes.

NIckel-catalyzed ring opening

In effort to utilize more abundant and affordable catalysts for ring-opening, Oshima et al. demonstrated the viability of nickel-catalyzed ring-opening of silacyclobutanes with aldehydes (1) [31] and terminal alkenes (2), [32] retaining stereoselectivity and regioselectivity.

Nickel-catalyzed ring-opening of silacyclobutanes with aldehydes (1) and terminal alkenes (2). NiCatalystSilacyclobutane2.png
Nickel-catalyzed ring-opening of silacyclobutanes with aldehydes (1) and terminal alkenes (2).

Transition-metal-catalyzed ring expansion

Ring expansion as a means to form a diverse array of sila-heterocycles, along with elucidating the underlying mechanisms governing this phenomena, remains an active area of research. In particular, ring expansion using silacyclobutanes has been useful in synthesizing cyclic silyl enol ethers which are useful precursors in organosilicon chemistry. [2]

Ring expansion has been shown to commence in a multitude of ways, such as insertion with SO2, [33] SO3, [34] phosphorus ylides, [35] acid chloride, [29] palladium catalysts, [29] platinum catalysts, [29] nickel catalysts, [31] rhodium catalysts, [36] along with others. [1] [2] Noteable reactions include palladium-catalyzed ring expansion cycloaddition of silacyclobutane with alkynes (1) [37] and nickel-catalyzed ring expansion of silacyclobutanes with aldehydes to form cyclic enol ethers (2) [31] . Further work has also showed that ring expansion of silacyclobutanes to five, six, seven, and eight-membered heterocycles can be achieved. [1]

Palladium-catalyzed ring expansion cycloaddition of silacyclobutane with alkynes (1) and nickel-catalyzed ring expansion of silacyclobutanes with aldehydes to form cyclic enol ethers (2) . RingOpeningSilacyclobutane.png
Palladium-catalyzed ring expansion cycloaddition of silacyclobutane with alkynes (1) and nickel-catalyzed ring expansion of silacyclobutanes with aldehydes to form cyclic enol ethers (2) .

Metal-free reactions

Carboxylation by CO2

In comparison to the numerous transition-metal catalyzed reactions noted above, metal-free ring opening or expansion reactions remain relatively rare. [1] Most notably, in 2018 Murakami et al. observed a carboxylation, ring expansion, and subsequent ring opening of silacyclobutane in the presence of only CO2 and no other additional activating agents. [38]

Carboxylation, ring expansion, and subsequent ring opening of silacyclobutane in the presence of only CO2 and no other additional activating agents. CO2RingExpansion.png
Carboxylation, ring expansion, and subsequent ring opening of silacyclobutane in the presence of only CO2 and no other additional activating agents.

Heat-directed ring opening

In some cases, ring opening of silacyclobutanes has also been observed under heat, such as that seen by O'Neil et al. who reported a chemoselective carbonyl allylation between alkoxyallylsilacyclobutanes and salicylaldehydes. [39] DFT calculations support that the electron-rich oxygen atom stabilizes the transition state during the process. [40]

Chemoselective carbonyl allylation between alkoxyallylsilacyclobutane and salicylaldehydes where the electron-rich oxygen atom stabilizes the transition state. Chemoselective carbonyl allylation.png
Chemoselective carbonyl allylation between alkoxyallylsilacyclobutane and salicylaldehydes where the electron-rich oxygen atom stabilizes the transition state.

Aldol addition

Due to their enhanced Lewis acidity, silacyclobutanes have been shown to react with aldehydes to form non catalyzed aldol addition products at accelerated rates relative to silyl enol derivatives of ketones or esters with aldehydes which proceed extraordinarily slow even at high temperatures. [41] [42] These reactions may be further accelerated from the addition of potassium tert-butoxide.

Reaction of silacyclobutanes with aldehydes to form non catalyzed aldol addition products. AldolSilacyclobutane.png
Reaction of silacyclobutanes with aldehydes to form non catalyzed aldol addition products.

Allyation reaction

Work by Meyers et al. showed that silacyclobutanes have stronger Lewis acidity than tetraalkylsilacyclobutanes and could activate a carbonyl compound in an allylation reaction without catalyst to yield a homoallylic alcohol product with high regio- and stereoselectivity. [43]

Allylation reaction with silacyclobutae to yield a homoallylic alcohol product. AllylationSilacyclobutane.png
Allylation reaction with silacyclobutae to yield a homoallylic alcohol product.

References

  1. 1 2 3 4 5 6 Huang, Jiapian; Liu, Fei; Wu, Xinyu; Chen, Jian-Qiang; Wu, Jie (2022). "Recent advances in the reactions of silacyclobutanes and their applications". Organic Chemistry Frontiers. 9 (10): 2840–2855. doi:10.1039/D2QO00410K. ISSN   2052-4129.
  2. 1 2 3 4 5 Mu, Qiu-Chao; Chen, Jing; Xia, Chun-Gu; Xu, Li-Wen (2018-11-01). "Synthesis of silacyclobutanes and their catalytic transformations enabled by transition-metal complexes". Coordination Chemistry Reviews. 374: 93–113. doi:10.1016/j.ccr.2018.06.015. ISSN   0010-8545.
  3. ↑ Laane, Jaan (1970-03-01). "Vibrational spectra and normal-coordinate analyses of silacyclobutanes". Spectrochimica Acta Part A: Molecular Spectroscopy. 26 (3): 517–540. Bibcode:1970AcSpA..26..517L. doi:10.1016/0584-8539(70)80099-X. ISSN   0584-8539.
  4. 1 2 Laane, Jaan; Lord, R. C. (1968-02-15). "Far-Infrared Spectra of Ring Compounds. III. Spectrum, Structure, and Ring-Puckering Potential of Silacyclobutane". The Journal of Chemical Physics. 48 (4): 1508–1513. Bibcode:1968JChPh..48.1508L. doi:10.1063/1.1668871. ISSN   0021-9606.
  5. 1 2 Gordon, Mark S.; Barton, Thomas J.; Nakano, Haruyuki (1997-12-01). "Ring Opening of Silacyclobutane". Journal of the American Chemical Society. 119 (49): 11966–11973. Bibcode:1997JAChS.11911966G. doi:10.1021/ja9715354. ISSN   0002-7863.
  6. ↑ Blake, Thomas A.; Xantheas, Sotiris S. (2006-09-01). "Structure, Vibrational Spectrum, and Ring Puckering Barrier of Cyclobutane". The Journal of Physical Chemistry A. 110 (35): 10487–10494. Bibcode:2006JPCA..11010487B. doi:10.1021/jp062472r. ISSN   1089-5639. PMID   16942054.
  7. ↑ Krapivin, A.M.; Mägi, M.; Svergun, V.I.; Zaharjan, R.Z.; Babich, E.D.; Ushakov, N.V. (April 1980). "The nmr study and cndo/2 molecular orbital calculation of silacyclobutanes". Journal of Organometallic Chemistry. 190 (1): 9–33. doi:10.1016/s0022-328x(00)82875-2. ISSN   0022-328X.
  8. ↑ Flowers, M. C.; Gusel'nikov, L. E. (1968). "A kinetic study of the gas-phase thermal decomposition of 1,1-dimethyl-1-silacyclobutane". Journal of the Chemical Society B: Physical Organic: 419. doi:10.1039/j29680000419. ISSN   0045-6470.
  9. ↑ Nametkin, N. S.; Vdovin, V. M.; Gusel'nikov, L. E.; Zav'yalov, V. I. (March 1966). "Formation of 1,3-disilacyclobutanes in the pyrolytic condensation of 1-silacyclobutanes". Bulletin of the Academy of Sciences, USSR Division of Chemical Science. 15 (3): 563. doi:10.1007/bf00846138. ISSN   0568-5230.
  10. ↑ Gusel'Nikov, L. E.; Flowers, M. C. (1967-01-01). "The thermal decomposition of 1,1-dimethyl-1-silacyclobutane and some reactions of an unstable intermediate containing a silicon–carbon double bond". Chemical Communications (London) (17): 864–865. doi:10.1039/C19670000864. ISSN   0009-241X.
  11. ↑ Tong, L.; Shi, Y. J. (January 2011). "Gas-phase reaction chemistry of 1,1-dimethyl-1-silacyclobutane as a precursor gas in the hot-wire chemical vapor deposition process — Formation of tetramethylsilane and trimethylsilane". Canadian Journal of Chemistry. 89 (1): 19–26. Bibcode:2011CaJCh..89...19T. doi:10.1139/V10-147. ISSN   0008-4042.
  12. ↑ Kipping, Frederic Stanley (1912-01-01). "CCXXIV.—Organic derivatives of silicon. Part XVII. Some condensation products of diphenylsilicanediol". Journal of the Chemical Society, Transactions. 101: 2125–2142. doi:10.1039/CT9120102125. ISSN   0368-1645.
  13. ↑ Kipping, Frederic Stanley; Sands, James Edwin (1921-01-01). "XCIV.—Organic derivatives of silicon. Part XXVI. Piperidine as an analytical reagent". Journal of the Chemical Society, Transactions. 119: 848–850. doi:10.1039/CT9211900848. ISSN   0368-1645.
  14. ↑ Sommer, Leo H.; Baum, Gerald A. (October 1954). "A Silicon-Containing 4-Ring". Journal of the American Chemical Society. 76 (19): 5002. Bibcode:1954JAChS..76Q5002S. doi:10.1021/ja01648a083. ISSN   0002-7863.
  15. ↑ Gilman, Henry.; Atwell, William H. (1964-07-01). "Small-Ring Organosilicon Compounds. I. A Comparison of the Reactivities of 1,1,2-Triphenyl-1-silacyclobutane and 1,1,2-Triphenyl-1-silacyclopentane". Journal of the American Chemical Society. 86 (13): 2687–2693. Bibcode:1964JAChS..86.2687G. doi:10.1021/ja01067a035. ISSN   0002-7863.
  16. ↑ Gilman, Henry.; Atwell, William H. (1964-07-01). "Small-Ring Organosilicon Compounds. I. A Comparison of the Reactivities of 1,1,2-Triphenyl-1-silacyclobutane and 1,1,2-Triphenyl-1-silacyclopentane". Journal of the American Chemical Society. 86 (13): 2687–2693. Bibcode:1964JAChS..86.2687G. doi:10.1021/ja01067a035. ISSN   0002-7863.
  17. ↑ de Boer, H. J. R.; Akkerman, O. S.; Bickelhaupt, F. (1987-04-10). "An investigation of the di-Grignard approach to metallabenzocyclobutenes of group 14". Journal of Organometallic Chemistry. 321 (3): 291–306. doi:10.1016/0022-328X(87)80301-7. ISSN   0022-328X.
  18. ↑ Kang, Kyung-Tae; Song, Hwan-Young; Seo, Hee-Chan (1985-05-05). "Synthesis of 4-substituted 1,1-di-t-butylbenzosilacyclobutenes". Chemistry Letters. 14 (5): 617–620. doi:10.1246/cl.1985.617. ISSN   0366-7022.
  19. ↑ Nametkin, N. S.; Vdovin, V. M.; Grinberg, P. L. (June 1964). "Telomerization of silicacyclobutanes". Bulletin of the Academy of Sciences, USSR Division of Chemical Science. 13 (6): 1055. doi:10.1007/bf01141674. ISSN   0568-5230.
  20. 1 2 3 Laane, J. (March 1967). "Synthesis of Silacyclobutane and Some Related Compounds". Journal of the American Chemical Society. 89 (5): 1144–1147. Bibcode:1967JAChS..89.1144L. doi:10.1021/ja00981a020. ISSN   0002-7863.
  21. 1 2 Auner, N.; Grobe, J. (1980-04-01). "Silaethene: I. Darstellung und charakterisierung von monosilacyclobutanen". Journal of Organometallic Chemistry. 188 (1): 25–52. doi:10.1016/S0022-328X(00)83695-5. ISSN   0022-328X.
  22. 1 2 Jones, Paul Ronald; Lim, Thomas F. O. (1977-12-01). "Silaethylene intermediates from .alpha.-lithiosilanes. 2. Reactions with chlorosilanes and 1,3-butadiene". Journal of the American Chemical Society. 99 (26): 8447–8451. Bibcode:1977JAChS..99.8447J. doi:10.1021/ja00468a011. ISSN   0002-7863.
  23. 1 2 Jones, Paul Ronald; Lim, Thomas F. O.; Pierce, Richard A. (1980-07-01). ".alpha.-Lithiosilanes. 4. Silaethylene cycloadditions with conjugated dienes". Journal of the American Chemical Society. 102 (15): 4970–4973. Bibcode:1980JAChS.102.4970J. doi:10.1021/ja00535a025. ISSN   0002-7863.
  24. 1 2 Sewald, Norbert; Ziche, Wolfgang; Wolff, Astrid; Auner, Norbert (1993-10-01). "Silaheterocycles. 26. Facile synthesis of silicon dichloro substituted 3-vinyl-1-silacyclobutanes from silene/butadiene [2+2] cycloaddition reactions: model compounds for vinylsilacyclobutane .fwdarw. silacyclohexene rearrangements". Organometallics. 12 (10): 4123–4134. doi:10.1021/om00034a055. ISSN   0276-7333.
  25. 1 2 3 4 Denmark, Scott E.; Sweis, Ramzi F. (2002-06-18). "Design and Implementation of New, Silicon-Based, Cross-Coupling Reactions: Importance of Silicon−Oxygen Bonds". Accounts of Chemical Research. 35 (10): 835–846. doi:10.1021/ar020001r. ISSN   0001-4842. PMID   12379136.
  26. 1 2 Denmark, Scott E.; Choi, Jun Young (1999-06-01). "Highly Stereospecific, Cross-Coupling Reactions of Alkenylsilacyclobutanes". Journal of the American Chemical Society. 121 (24): 5821–5822. Bibcode:1999JAChS.121.5821D. doi:10.1021/ja9908117. ISSN   0002-7863.
  27. 1 2 Denmark, Scott E.; Wang, Zhigang (2000). "1-Methyl-1-vinyl- and 1-Methyl-1-(prop-2-enyl)silacyclobutane: Reagents for Palladium-Catalyzed Cross-Coupling Reactions of Aryl Halides". Synthesis. 2000 (7): 999–1003. doi:10.1055/s-2000-6292. ISSN   0039-7881.
  28. ↑ Weyenberg, Donald R.; Nelson, Lee E. (1965-08-01). "Platinum-Catalyzed Reactions of Silacyclobutanes and 1,3-Disilacyclobutanes". The Journal of Organic Chemistry. 30 (8): 2618–2621. doi:10.1021/jo01019a027. ISSN   0022-3263.
  29. 1 2 3 4 Tanaka, Yoshifumi; Yamashita, Hiroshi; Tanaka, Masato (1996-03-19). "Palladium- and Platinum-Catalyzed Reactions of Silacyclobutanes with Acid Chlorides Affording Cyclic Silyl Enol Ethers and/or 3-(Chlorosilyl)propyl Ketones". Organometallics. 15 (6): 1524–1526. doi:10.1021/om950786n. ISSN   0276-7333.
  30. ↑ Tanaka, Yoshifumi; Nishigaki, Atsushi; Kimura, Yutaka; Yamashita, Masakazu (2001). "Unexpected regioselectivity in the palladium-catalyzed reaction of silacyclobutanes with aryl iodides". Applied Organometallic Chemistry. 15 (8): 667–670. doi:10.1002/aoc.206. ISSN   1099-0739.
  31. 1 2 3 4 5 Hirano, Koji; Yorimitsu, Hideki; Oshima, Koichiro (2006-02-01). "Nickel-Catalyzed Reactions of Silacyclobutanes with Aldehydes: Ring Opening and Ring Expansion Reaction". Organic Letters. 8 (3): 483–485. doi:10.1021/ol0527577. ISSN   1523-7060. PMID   16435865.
  32. 1 2 Hirano, Koji; Yorimitsu, Hideki; Oshima, Koichiro (2007-05-01). "Nickel-Catalyzed Regio- and Stereoselective Silylation of Terminal Alkenes with Silacyclobutanes: Facile Access to Vinylsilanes from Alkenes". Journal of the American Chemical Society. 129 (19): 6094–6095. Bibcode:2007JAChS.129.6094H. doi:10.1021/ja070938t. ISSN   0002-7863. PMID   17441723.
  33. ↑ Dubac, Jacques; Mazerolles, Pierre; Joly, Monique (1978-06-27). "Stereochimie de la sulfonation d'organosilanes". Journal of Organometallic Chemistry. 153 (3): 289–298. doi:10.1016/S0022-328X(00)92051-5. ISSN   0022-328X.
  34. ↑ Dubac, J.; Mazerolles, P.; Joly, M.; Kitching, W.; Fong, C. W.; Atwell, W. H. (1970-11-01). "Sultones et sultines organométalliques V. Réactions d'insertion de l'anhydride sulfureux dans la liaison siliciumcarbone: sultines organosiliciques". Journal of Organometallic Chemistry. 25 (1): C20 –C22. doi:10.1016/S0022-328X(00)86189-6. ISSN   0022-328X.
  35. ↑ Schmidbaur, Hubert; Wolf, Walter (1973). "Anormale Silacyclobutan-Ringöffnung durch Alkyliden-trialkylphosphorane". Angewandte Chemie. 85 (8): 344–345. Bibcode:1973AngCh..85..344S. doi:10.1002/ange.19730850807. ISSN   1521-3757.
  36. ↑ Zhang, Qing-Wei; An, Kun; Liu, Li-Chuan; Guo, Shuangxi; Jiang, Chenran; Guo, Huifang; He, Wei (2016-04-13). "Rhodium-Catalyzed Intramolecular C−H Silylation by Silacyclobutanes". Angewandte Chemie International Edition. 55 (21): 6319–6323. Bibcode:2016ACIE...55.6319Z. doi:10.1002/anie.201602376. ISSN   1433-7851. PMID   27073004.
  37. 1 2 Chen, Ling; Cao, Jian; Xu, Zheng; Zheng, Zhan-Jiang; Cui, Yu-Ming; Xu, Li-Wen (2016). "Lewis acid catalyzed [2+2] cycloaddition of ynamides and propargyl silyl ethers: synthesis of alkylidenecyclobutenones and their reactivity in ring-opening and ring expansion". Chemical Communications. 52 (61): 9574–9577. doi:10.1039/C6CC04648G. ISSN   1359-7345. PMID   27387596.
  38. 1 2 Ishida, Naoki; Okumura, Shintaro; Kawasaki, Tairin; Murakami, Masahiro (2018). "2-Arylsilacyclobutane as a Latent Carbanion Reacting with CO2". Angewandte Chemie International Edition. 57 (35): 11399–11403. Bibcode:2018ACIE...5711399I. doi:10.1002/anie.201805333. ISSN   1521-3773. PMID   30019406.
  39. 1 2 Spaltenstein, Paul; Cummins, Elizabeth J.; Yokuda, Kelly-Marie; Kowalczyk, Tim; Clark, Timothy B.; O’Neil, Gregory W. (2019-04-05). "Chemoselective Carbonyl Allylations with Alkoxyallylsiletanes". The Journal of Organic Chemistry. 84 (7): 4421–4428. doi:10.1021/acs.joc.8b03028. ISSN   0022-3263. PMC   6767911 . PMID   30811929.
  40. 1 2 Ito, Hajime; Ujita, Yasuaki; Tateiwa, Jun-ichi; Sonoda, Motohiro; Hosomi, Akira (1998). "Intramolecular hydrogen bond-promoted C–C bond formation: reaction rate enhancement and regioselective allylation of carbonyl compounds". Chemical Communications (22): 2443–2444. doi:10.1039/a807172a. ISSN   1359-7345.
  41. 1 2 Myers, Andrew G.; Kephart, Susan E.; Chen, Hou (1992-09-01). "Silicon-directed aldol reactions. Rate acceleration by small rings". Journal of the American Chemical Society. 114 (20): 7922–7923. Bibcode:1992JAChS.114.7922M. doi:10.1021/ja00046a054. ISSN   0002-7863.
  42. 1 2 Denmark, Scott E.; Griedel, Brian D.; Coe, Diane M.; Schnute, Mark E. (1994-08-01). "Chemistry of Enoxysilacyclobutanes: Highly Selective Uncatalyzed Aldol Additions". Journal of the American Chemical Society. 116 (16): 7026–7043. Bibcode:1994JAChS.116.7026D. doi:10.1021/ja00095a004. ISSN   0002-7863.
  43. 1 2 Matsumoto, Kozo; Oshima, Koichiro; Utimoto, Kiitiro (1994-11-01). "Noncatalyzed Stereoselective Allylation of Carbonyl Compounds with Allylsilacyclobutanes". The Journal of Organic Chemistry. 59 (23): 7152–7155. doi:10.1021/jo00102a052. ISSN   0022-3263.
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