John Perry Wolfe | |
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![]() Wolfe in 2014 | |
Born | |
Alma mater | University of Colorado, Boulder, Massachusetts Institute of Technology, University of California, Irvine |
Scientific career | |
Fields | Organic chemistry, Organometallic chemistry, New Synthetic Methods, Catalysis, Natural Product Synthesis |
Institutions | University of Michigan |
Doctoral advisor | Stephen L. Buchwald |
Other academic advisors | Larry E. Overman |
John Perry Wolfe (born August 12, 1970) is an American chemist and a professor of chemistry at the University of Michigan. [1] He is best known for palladium-catalyzed C-C and C-N bond formation reactions. He was also one of the key scientists in the development of Buchwald ligands, one of which is appropriately named "JohnPhos" after him. Wolfe has taught at the University of Michigan since 2002.
John P. Wolfe was born in Greeley, Colorado. He graduated from the University of Colorado, Boulder in 1994 with a B.A. in Chemistry. During his undergraduate career, he served as an undergraduate research assistant for Professor Gary A. Molander, focusing on the development of a SmI
2 -promoted alternative to the cyanoacetic ester synthesis. [2]
After receiving his bachelor's degree from Colorado in 1994, he entered Massachusetts Institute of Technology (MIT), where he later earned his Ph.D. under Professor Stephen L. Buchwald in 1999 . During his five years at MIT, Wolfe co-authored 9 patents and 20 publications. Upon the completion of his Ph.D., he moved to University of California, Irvine, where he joined Professor Larry E. Overman and his research group as a National Institute of Health (NIH) National Research Service Award (NRSA) postdoctoral fellow. [3]
In 2002, Wolfe moved to Ann Arbor, MI, where he joined the University of Michigan faculty. Since then his research has focused on numerous topics in chemistry, which altogether direct towards the development of new metal-catalyzed reactions for the synthesis of interesting, biologically active compounds. [4] At Michigan, Wolfe is one of the most admired professors in the chemistry department for his outstanding lectures, especially in organic chemistry. The University has recognized his contributions by presenting him with teaching awards, and his students quote him as "the best professor [they]'ve had at University of Michigan", "he make[s] organic chemistry fun and not intimidating" and "words cannot express how great of a teacher and person he is". [5]
John P. Wolfe has developed many palladium-catalyzed alkene carboamination reactions. These reactions contribute greatly to the synthesis of nitrogen heterocycles, which are commonly found in both pharmaceuticals and natural products. [6] [7] [8] Common applications include the synthesis of pyrrolidines, and three-, five-, six- and seven-membered heterocycles such as pyrazolidines, aziridines, morpholines. His scope extends further to polycyclic heterocycles and the total synthesis of (+)-aphanorphine. These alkene aminoarylations take place via the cross-coupling of aryl or alkenyl halides with simple aminoalkene substrates to generate the heterocyclic ring with formation of a C-N bond and a C-C bond. [9]
One area of his works focuses on the Pd(0)-catalyzed alkene aminoarylation:
Pyrrolidines can be efficiently generated via Pd(0)-catalyzed alkene aminoarylation reactions (Scheme 1). The advantages of this method are the wide substrate scope (substrates bearing N-aryl, N-acetyl, N-Boc, and N-Cbz groups) and good stereoselectivity. [10]
The reaction is initiated by oxidative addition of the aryl bromide to Pd(0) (1), proceeded by the formation of the key intermediate palladium(aryl)amido complex 2, which then undergoes intramolecular syn-migratory insertion of the alkene into the Pd-N bond to yield 3 to generate the product via reductive elimination (Scheme 2). [11]
During Wolfe’s graduate career at MIT with Professor Stephen L. Buchwald, he was involved in developing dialkylbiaryl phosphine ligands (now referred to as "Buchwald ligands") that are highly efficient in palladium-catalyzed reactions. One of these ligands – JohnPhos - was named after him and is now commercially available. [12]
In general, JohnPhos is a ligand for the Buchwald-Hartwig Cross Coupling reaction, C-X bond formation, the Heck reaction and Suzuki-Miyaura coupling. [13] JohnPhos is a particularly effective ligand for the palladium-catalyzed amination of aryl chlorides, bromides, and triflates. The ligand allows the reactions to take place at room-temperature, and performs well for a wide range of different substrate combinations at 80-110 °C, which includes chloropyridines and functionalized aryl halides and triflates. JohnPhos is particularly useful for aminations of –neutral or electron rich aryl chlorides with a wide variety of amine coupling partners. An example of the catalytic amination of an aryl chloride with N-methylaniline at room temperature is shown in Scheme 3. [14]
Although the high reactivity of the ligand is not completely understood, Buchwald et al. suggest some structural factors that contribute to their effectiveness: the electron rich phosphine group may help the acceleration of the oxidative addition step, [15] the steric bulk of the ligands may accelerate the C-N bond forming reductive elimination, [16] and the π-system of the ortho aromatic group on the ligand may participate in an interaction with the unoccupied metal d-orbital. [17] Another hypothesis is that the metal-arene interaction could stabilize the catalyst. The arene from the aryl halide is forced to orient perpendicularly to the N-Pd bond, which should stereoelectronically favor reductive elimination. [18] [19]
Wolfe has received many honors and awards, [20] including the following:
The Heck reaction is the chemical reaction of an unsaturated halide with an alkene in the presence of a base and a palladium catalyst to form a substituted alkene. It is named after Tsutomu Mizoroki and Richard F. Heck. Heck was awarded the 2010 Nobel Prize in Chemistry, which he shared with Ei-ichi Negishi and Akira Suzuki, for the discovery and development of this reaction. This reaction was the first example of a carbon-carbon bond-forming reaction that followed a Pd(0)/Pd(II) catalytic cycle, the same catalytic cycle that is seen in other Pd(0)-catalyzed cross-coupling reactions. The Heck reaction is a way to substitute alkenes.
The Stille reaction is a chemical reaction widely used in organic synthesis. The reaction involves the coupling of two organic groups, one of which is carried as an organotin compound (also known as organostannanes). A variety of organic electrophiles provide the other coupling partner. The Stille reaction is one of many palladium-catalyzed coupling reactions.
The Suzuki reaction or Suzuki coupling is an organic reaction that uses a palladium complex catalyst to cross-couple a boronic acid to an organohalide. It was first published in 1979 by Akira Suzuki, and he shared the 2010 Nobel Prize in Chemistry with Richard F. Heck and Ei-ichi Negishi for their contribution to the discovery and development of noble metal catalysis in organic synthesis. This reaction is sometimes telescoped with the related Miyaura borylation; the combination is the Suzuki–Miyaura reaction. It is widely used to synthesize polyolefins, styrenes, and substituted biphenyls.
The Sonogashira reaction is a cross-coupling reaction used in organic synthesis to form carbon–carbon bonds. It employs a palladium catalyst as well as copper co-catalyst to form a carbon–carbon bond between a terminal alkyne and an aryl or vinyl halide.
Organopalladium chemistry is a branch of organometallic chemistry that deals with organic palladium compounds and their reactions. Palladium is often used as a catalyst in the reduction of alkenes and alkynes with hydrogen. This process involves the formation of a palladium-carbon covalent bond. Palladium is also prominent in carbon-carbon coupling reactions, as demonstrated in tandem reactions.
Palladium(II) acetate is a chemical compound of palladium described by the formula [Pd(O2CCH3)2]n, abbreviated [Pd(OAc)2]n. It is more reactive than the analogous platinum compound. Depending on the value of n, the compound is soluble in many organic solvents and is commonly used as a catalyst for organic reactions.
In organic chemistry, the Buchwald–Hartwig amination is a chemical reaction for the synthesis of carbon–nitrogen bonds via the palladium-catalyzed coupling reactions of amines with aryl halides. Although Pd-catalyzed C–N couplings were reported as early as 1983, Stephen L. Buchwald and John F. Hartwig have been credited, whose publications between 1994 and the late 2000s established the scope of the transformation. The reaction's synthetic utility stems primarily from the shortcomings of typical methods for the synthesis of aromatic C−N bonds, with most methods suffering from limited substrate scope and functional group tolerance. The development of the Buchwald–Hartwig reaction allowed for the facile synthesis of aryl amines, replacing to an extent harsher methods while significantly expanding the repertoire of possible C−N bond formations.
1,1′-Bis(diphenylphosphino)ferrocene, commonly abbreviated dppf, is an organophosphorus compound commonly used as a ligand in homogeneous catalysis. It contains a ferrocene moiety in its backbone, and is related to other bridged diphosphines such as 1,2-bis(diphenylphosphino)ethane (dppe).
XPhos is a phosphine ligand derived from biphenyl. Its palladium complexes exhibit high activity for Buchwald-Hartwig amination reactions involving aryl chlorides and aryl tosylates. Both palladium and copper complexes of the compound exhibit high activity for the coupling of aryl halides and aryl tosylates with various amides. It is also an efficient ligand for several commonly used C–C bond-forming cross-coupling reactions, including the Negishi, Suzuki, and the copper-free Sonogashira coupling reactions. It is especially efficient and general when employed as a (2-aminobiphenyl)-cyclometalated palladium mesylate precatalyst complex, XPhos-G3-Pd, which is commercially available and stable to bench storage. The ligand itself also has convenient handling characteristics as a crystalline, air-stable solid.
The intramolecular Heck reaction (IMHR) in chemistry is the coupling of an aryl or alkenyl halide with an alkene in the same molecule. The reaction may be used to produce carbocyclic or heterocyclic organic compounds with a variety of ring sizes. Chiral palladium complexes can be used to synthesize chiral intramolecular Heck reaction products in non-racemic form.
[1,1'‑Bis(diphenylphosphino)ferrocene]palladium(II) dichloride is a palladium complex containing the bidentate ligand 1,1'-bis(diphenylphosphino)ferrocene (dppf), abbreviated as [(dppf)PdCl2]. This commercially available material can be prepared by reacting dppf with a suitable nitrile complex of palladium dichloride:
The White catalyst is a transition metal coordination complex named after the chemist by whom it was first synthesized, M. Christina White, a professor at the University of Illinois. The catalyst has been used in a variety of allylic C-H functionalization reactions of α-olefins. In addition, it has been shown to catalyze oxidative Heck reactions.
John F. Hartwig is an American organometallic chemist who holds the position of Henry Rapoport Professor of Chemistry at the University of California, Berkeley. His laboratory traditionally focuses on developing transition metal-catalyzed reactions. Hartwig is known for helping develop the Buchwald–Hartwig amination, a chemical reaction used in organic chemistry for the synthesis of carbon–nitrogen bonds via the palladium-catalyzed cross-coupling of amines with aryl halides.
Alkene carboamination is the simultaneous formation of C–N and C–C bonds across an alkene. This method represents a powerful strategy to build molecular complexity with up to two stereocenters in a single operation. Generally, there are four categories of reaction modes for alkene carboamination. The first class is cyclization reactions, which will form a N-heterocycle as a result. The second class has been well established in the last decade. Alkene substrates with a tethered nitrogen nucleophile have been used in these transformations to promote intramolecular aminocyclization. While intermolecular carboamination is extremely hard, people have developed a strategy to combine the nitrogen and carbon part, which is known as the third class. The most general carboamination, which takes three individual parts and couples them together is still underdeveloped.
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.
Janis Louie is a Chemistry professor and Henry Eyring Fellow at The University of Utah. Louie contributes to the chemistry world with her research in inorganic, organic, and polymer chemistry.
In organic chemistry, hydrovinylation is the formal insertion of an alkene into the C-H bond of ethylene. The more general reaction, hydroalkenylation, is the formal insertion of an alkene into the C-H bond of any terminal alkene. The reaction is catalyzed by metal complexes. A representative reaction is the conversion of styrene and ethylene to 3-phenybutene:
Heterobimetallic catalysis is an approach to catalysis that employs two different metals to promote a chemical reaction. Included in this definition are cases where: 1) each metal activates a different substrate, 2) both metals interact with the same substrate, and 3) only one metal directly interacts with the substrate(s), while the second metal interacts with the first.
Mark Stradiotto is a Canadian chemist. He is currently the Arthur B. McDonald Research Chair and the Alexander McLeod Professor of Chemistry in the Department of Chemistry at Dalhousie University.
Miyaura borylation, also known as the Miyaura borylation reaction, is a named reaction in organic chemistry that allows for the generation of boronates from vinyl or aryl halides with the cross-coupling of bis(pinacolato)diboron in basic conditions with a catalyst such as PdCl2(dppf). The resulting borylated products can be used as coupling partners for the Suzuki reaction.