Dean Toste | |
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Born | Francisco Dean Toste 1971 (age 52–53) |
Alma mater | University of Toronto B.Sc. (1993) M.Sc. (1995) Stanford University Ph.D. (2000) |
Known for | Organogold chemistry asymmetric ion-pairing catalysis |
Scientific career | |
Fields | Chemistry |
Institutions | University of California, Berkeley |
Thesis | Part A. Phenols in palladium catalyzed reactions. Enantioselective total syntheses of (-)-galanthamine, (-)-aflatoxin B(1) and (-)-calanolide A and B. Part B. Ruthenium catalyzed carbon-carbon bond forming reactions (2001) |
Doctoral advisor | Barry Trost |
Other academic advisors | Robert H. Grubbs Ian Still |
Website | www |
F. Dean Toste (born 1971 in Terceira, Azores, Portugal) is the Gerald E. K. Branch Distinguished Professor of Chemistry at the University of California, Berkeley and faculty scientist at the chemical sciences division of Lawrence Berkeley National Lab. He is a prominent figure in the field of organic chemistry and is best known for his contributions to gold chemistry [1] and asymmetric ion-pairing catalysis. [2] Toste was elected a member of the National Academy of Sciences in 2020, [3] [4] and a member of the American Academy of Arts and Sciences in 2018. [5]
Toste attended the University of Toronto for his undergraduate and masters studies in the group of Ian Still. [6] With Still, Toste developed several novel reactions of thiocyanates [7] [8] [9] [10] that were then applied towards the synthesis of the natural product Varacin. [11] He earned his B.Sc. in 1993 and his M.Sc. in 1995. Toste attended graduate school at Stanford University, earning his PhD under the supervision of Barry Trost in 2000 [12] While at Stanford, Toste published twenty-four publications on a range of topics, including phenols in palladium-catalyzed reactions, [13] [14] [15] and ruthenium-catalyzed carbon-carbon bond forming reactions. [16] [17] He also completed the enantioselective total syntheses of the natural products (−)-galanthamine, [18] (−)-aflatoxin B1 [19] [20] and (−)-calanolide A and B. [21]
From 2001 to 2002, Toste conducted postdoctoral studies at the California Institute of Technology with Robert H. Grubbs, where he worked on ruthenium-catalyzed cross-metathesis variants of the olefin metathesis reaction. [22] [23] [24]
Toste joined the faculty at Berkeley in 2002 as an assistant professor. He was promoted to associate professor in 2006, and professor in 2009. In 2017, Toste was appointed the Gerald E. K. Branch Distinguished Professor. He has served as a faculty scientist at the chemical sciences division of Lawrence Berkeley National Lab since 2007. [25]
Toste is the recipient of numerous awards for his work, including the Janssen Prize for Creativity in Organic Synthesis in 2018, [26] the Humboldt Research Award in 2016, [27] the Catalysis in Organic Chemistry Award from the Royal Society of Chemistry in 2018, and the American Chemical Society Cope Scholar and E. J. Corey Awards. [25]
The Ullmann reaction or Ullmann coupling, named after Fritz Ullmann, couples two aryl or alkyl groups with the help of copper. The reaction was first reported by Ullmann and his student Bielecki in 1901. It has been later shown that palladium and nickel can also be effectively used.
Aflatoxin total synthesis concerns the total synthesis of a group of organic compounds called aflatoxins. These compounds occur naturally in several fungi. As with other chemical compound targets in organic chemistry, the organic synthesis of aflatoxins serves various purposes. Traditionally it served to prove the structure of a complex biocompound in addition to evidence obtained from spectroscopy. It also demonstrates new concepts in organic chemistry and opens the way to molecular derivatives not found in nature. And for practical purposes, a synthetic biocompound is a commercial alternative to isolating the compound from natural resources. Aflatoxins in particular add another dimension because it is suspected that they have been mass-produced in the past from biological sources as part of a biological weapons program.
The Negishi coupling is a widely employed transition metal catalyzed cross-coupling reaction. The reaction couples organic halides or triflates with organozinc compounds, forming carbon-carbon bonds (C-C) in the process. A palladium (0) species is generally utilized as the metal catalyst, though nickel is sometimes used. A variety of nickel catalysts in either Ni0 or NiII oxidation state can be employed in Negishi cross couplings such as Ni(PPh3)4, Ni(acac)2, Ni(COD)2 etc.
A carbometallation is any reaction where a carbon-metal bond reacts with a carbon-carbon π-bond to produce a new carbon-carbon σ-bond and a carbon-metal σ-bond. The resulting carbon-metal bond can undergo further carbometallation reactions or it can be reacted with a variety of electrophiles including halogenating reagents, carbonyls, oxygen, and inorganic salts to produce different organometallic reagents. Carbometallations can be performed on alkynes and alkenes to form products with high geometric purity or enantioselectivity, respectively. Some metals prefer to give the anti-addition product with high selectivity and some yield the syn-addition product. The outcome of syn and anti- addition products is determined by the mechanism of the carbometallation.
Barry M. Trost is an American chemist who is the Job and Gertrud Tamaki Professor Emeritus in the School of Humanities and Sciences at Stanford University. The Tsuji-Trost reaction and the Trost ligand are named after him. He is prominent for advancing the concept of atom economy.
The Liebeskind–Srogl coupling reaction is an organic reaction forming a new carbon–carbon bond from a thioester and a boronic acid using a metal catalyst. It is a cross-coupling reaction. This reaction was invented by and named after Jiri Srogl from the Academy of Sciences, Czech Republic, and Lanny S. Liebeskind from Emory University, Atlanta, Georgia, USA. There are three generations of this reaction, with the first generation shown below. The original transformation used catalytic Pd(0), TFP = tris(2-furyl)phosphine as an additional ligand and stoichiometric CuTC = copper(I) thiophene-2-carboxylate as a co-metal catalyst. The overall reaction scheme is shown below.
Metal carbon dioxide complexes are coordination complexes that contain carbon dioxide ligands. Aside from the fundamental interest in the coordination chemistry of simple molecules, studies in this field are motivated by the possibility that transition metals might catalyze useful transformations of CO2. This research is relevant both to organic synthesis and to the production of "solar fuels" that would avoid the use of petroleum-based fuels.
Hydrogen auto-transfer, also known as borrowing hydrogen, is the activation of a chemical reaction by temporary transfer of two hydrogen atoms from the reactant to a catalyst and return of those hydrogen atoms back to a reaction intermediate to form the final product. Two major classes of borrowing hydrogen reactions exist: (a) those that result in hydroxyl substitution, and (b) those that result in carbonyl addition. In the former case, alcohol dehydrogenation generates a transient carbonyl compound that is subject to condensation followed by the return of hydrogen. In the latter case, alcohol dehydrogenation is followed by reductive generation of a nucleophile, which triggers carbonyl addition. As borrowing hydrogen processes avoid manipulations otherwise required for discrete alcohol oxidation and the use of stoichiometric organometallic reagents, they typically display high levels of atom-economy and, hence, are viewed as examples of Green chemistry.
The Tsuji–Trost reaction is a palladium-catalysed substitution reaction involving a substrate that contains a leaving group in an allylic position. The palladium catalyst first coordinates with the allyl group and then undergoes oxidative addition, forming the π-allyl complex. This allyl complex can then be attacked by a nucleophile, resulting in the substituted product.
A Josiphos ligand is a type of chiral diphosphine which has been modified to be substrate-specific; they are widely used for enantioselective synthesis. They are widely used in asymmetric catalysis.
The Catellani reaction was discovered by Marta Catellani and co-workers in 1997. The reaction uses aryl iodides to perform bi- or tri-functionalization, including C-H functionalization of the unsubstituted ortho position(s), followed a terminating cross-coupling reaction at the ipso position. This cross-coupling cascade reaction depends on the ortho-directing transient mediator, norbornene.
In organic chemistry, the Fujiwara–Moritani reaction is a type of cross coupling reaction where an aromatic C-H bond is directly coupled to an olefinic C-H bond, generating a new C-C bond. This reaction is performed in the presence of a transition metal, typically palladium. The reaction was discovered by Yuzo Fujiwara and Ichiro Moritani in 1967. An external oxidant is required to this reaction to be run catalytically. Thus, this reaction can be classified as a C-H activation reaction, an oxidative Heck reaction, and a C-H olefination. Surprisingly, the Fujiwara–Moritani reaction was discovered before the Heck reaction.
Dialkylbiaryl phosphine ligands are phosphine ligands that are used in homogeneous catalysis. They have proved useful in Buchwald-Hartwig amination and etherification reactions as well as Negishi cross-coupling, Suzuki-Miyaura cross-coupling, and related reactions. In addition to these Pd-based processes, their use has also been extended to transformations catalyzed by nickel, gold, silver, copper, rhodium, and ruthenium, among other transition metals.
Vinylcyclopropane [5+2] cycloaddition is a type of cycloaddition between a vinylcyclopropane (VCP) and an olefin or alkyne to form a seven-membered ring.
A transition metal phosphido complex is a coordination complex containing a phosphido ligand (R2P, where R = H, organic substituent). With two lone pairs on phosphorus, the phosphido anion (R2P−) is comparable to an amido anion (R2N−), except that the M-P distances are longer and the phosphorus atom is more sterically accessible. For these reasons, phosphido is often a bridging ligand. The -PH2 ion or ligand is also called phosphanide or phosphido ligand.
The metallo-ene reaction is a chemical reaction employed within organic synthesis. Mechanistically similar to the classic ene reaction, the metallo-ene reaction involves a six-member cyclic transition state that brings an allylic species and an alkene species together to undergo a rearrangement. The initial allylic group migrates to one terminus of the alkene reactant and a new carbon-carbon sigma bond is formed between the allylic species and the other terminus of the alkene reactant. In the metallo-ene reaction, a metal ion acts as the migrating group rather than a hydrogen atom as in the classic ene reaction.
β-Carbon elimination is a type of reaction in organometallic chemistry wherein an allyl ligand bonded to a metal center is broken into the corresponding metal-bonded alkyl (aryl) ligand and an alkene. It is a subgroup of elimination reactions. Though less common and less understood than β-hydride elimination, it is an important step involved in some olefin polymerization processes and transition-metal-catalyzed organic reactions.
T.V. (Babu) RajanBabu is an organic chemist who holds the position of Distinguished Professor of Chemistry in the College of Arts and Sciences at the Ohio State University. His laboratory traditionally focuses on developing transition metal-catalyzed reactions. RajanBabu is known for helping develop the Nugent-RajanBabu reagent, a chemical reagent used in synthetic organic chemistry as a single electron reductant.
Mono-N-protected amino acid (MPAA) is a bifunctional ligand that plays a key role in C–H functionalizations by accelerating the reaction rate and imparting specified chirality into the product. Amino acids are ideal building blocks for chiral ligand synthesis due to the cost, accessibility, large variety, solubility, and inherent chirality. Naturally occurring amino acids are transformed into chiral MPAA ligands that, upon coordination to metal complexes, allow reactions to occur that are otherwise energetically unfavorable. Great strides in the development of MPAA ligands over the past two decades have led to the integral role that enantioselective catalysis now plays in complex organic synthesis.
Jiro Tsuji was a Japanese chemist, notable for his discovery of organometallic reactions, including the Tsuji-Trost reaction, the Tsuji-Wilkinson decarbonylation, and the Tsuji-Wacker reaction.