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Kapat A, Sperger T, Guven S, Schoenebeck F. E-Olefins through intramolecular radical relocation. Science 2019; 363:391-396. [PMID: 30679370 DOI: 10.1126/science.aav1610] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 12/17/2018] [Indexed: 01/20/2023]
Abstract
Full control over the selectivity of carbon-carbon double-bond migrations would enable access to stereochemically defined olefins that are central to the pharmaceutical, food, fragrance, materials, and petrochemical arenas. The vast majority of double-bond migrations investigated over the past 60 years capitalize on precious-metal hydrides that are frequently associated with reversible equilibria, hydrogen scrambling, incomplete E/Z stereoselection, and/or high cost. Here, we report a fundamentally different, radical-based approach. We showcase a nonprecious, reductant-free, and atom-economical nickel (Ni)(I)-catalyzed intramolecular 1,3-hydrogen atom relocation to yield E-olefins within 3 hours at room temperature. Remote installations of E-olefins over extended distances are also demonstrated.
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Affiliation(s)
- Ajoy Kapat
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Theresa Sperger
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Sinem Guven
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Franziska Schoenebeck
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
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2
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Feng J, Holmes M, Krische MJ. Acyclic Quaternary Carbon Stereocenters via Enantioselective Transition Metal Catalysis. Chem Rev 2017; 117:12564-12580. [PMID: 28910092 PMCID: PMC5651685 DOI: 10.1021/acs.chemrev.7b00385] [Citation(s) in RCA: 301] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Whereas numerous asymmetric methods for formation of quaternary carbon stereocenters in cyclic systems have been documented, the construction of acyclic quaternary carbon stereocenters with control of absolute stereochemistry remains a formidable challenge. This Review summarizes enantioselective methods for the construction of acyclic quaternary carbon stereocenters from achiral or chiral racemic reactants via transition metal catalysis.
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Affiliation(s)
- Jiajie Feng
- Department of Chemistry, Welch Hall (A5300), University of Texas at Austin , 105 East 24th Street, Austin, Texas 78712, United States
| | - Michael Holmes
- Department of Chemistry, Welch Hall (A5300), University of Texas at Austin , 105 East 24th Street, Austin, Texas 78712, United States
| | - Michael J Krische
- Department of Chemistry, Welch Hall (A5300), University of Texas at Austin , 105 East 24th Street, Austin, Texas 78712, United States
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3
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Patel HH, Sigman MS. Enantioselective Palladium-Catalyzed Alkenylation of Trisubstituted Alkenols To Form Allylic Quaternary Centers. J Am Chem Soc 2016; 138:14226-14229. [PMID: 27768842 DOI: 10.1021/jacs.6b09649] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this report, we describe the generation of remote allylic quaternary stereocenters β, γ, and δ relative to a carbonyl in high enantioselectivity. We utilize a redox-relay Heck reaction between alkenyl triflates and acyclic trisubstituted alkenols of varying chain-lengths. A wide array of terminal (E)-alkenyl triflates are suitable for this process. The utility of this functionalization is validated further by conversion of the products, via simple organic processes to access remotely functionalized chiral tertiary acid, amine, and alcohol products.
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Affiliation(s)
- Harshkumar H Patel
- Department of Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Matthew S Sigman
- Department of Chemistry, University of Utah , 315 South 1400 East, Salt Lake City, Utah 84112, United States
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4
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Hong X, Wang J, Yang YF, He L, Ho CY, Houk KN. Computational Exploration of Mechanism and Selectivities of (NHC)Nickel(II)hydride-Catalyzed Hydroalkenylations of Styrene with α-Olefins. ACS Catal 2015. [DOI: 10.1021/acscatal.5b01075] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Xin Hong
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Jinglin Wang
- Department
of Chemistry, South University of Science and Technology of China (SUSTC), Shenzhen 518055, P.R. China
| | - Yun-Fang Yang
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Lisi He
- Shenzhen
Research Institute, The Chinese University of Hong Kong, Shatin NT, Hong Kong, P.R. China
| | - Chun-Yu Ho
- Department
of Chemistry, South University of Science and Technology of China (SUSTC), Shenzhen 518055, P.R. China
- Shenzhen
Research Institute, The Chinese University of Hong Kong, Shatin NT, Hong Kong, P.R. China
| | - K. N. Houk
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
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Timsina YN, Sharma RK, RajanBabu TV. Cobalt-Catalysed Asymmetric Hydrovinylation of 1,3-Dienes. Chem Sci 2015; 6:3994-4008. [PMID: 26430505 PMCID: PMC4587399 DOI: 10.1039/c5sc00929d] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 04/22/2015] [Indexed: 02/06/2023] Open
Abstract
In the presence of bidentate 1,n-bis-diphenylphosphinoalkane-CoCl2 complexes {Cl2Co[P~P]} and Me3Al or methylaluminoxane, acyclic (E)-1,3-dienes react with ethylene (1 atmosphere) to give excellent yields of hydrovinylation products. The regioselectivity (1,4- or 1,2-addition) and the alkene configuration (E- or Z-) of the resulting product depend on the nature of the ligand and temperature at which the reaction is carried out. Cobalt(II)-complexes of 1,1-diphenylphosphinomethane and similar ligands with narrow bite angles give mostly 1,2-addition, retaining the E-geometry of the original diene. Complexes of most other ligands at low temperature (-40 °C) give almost exclusively a single branched product, (Z)-3-alkylhexa-1,4-diene, which arises from a 1,4-hydrovinylation reaction. A minor product is the linear adduct, a 5-alkyl-hexa-1,4-diene, also arising from a 1,4-addition of ethylene. As the temperature is increased, a higher proportion of the major 1,4-adduct appears as the (E)-isomer. The unexpectedly high selectivity seen in the Co-catalysed reaction as compared to the corresponding Ni-catalysed reaction can be rationalized by invoking the intermediacy of an η4-[(diene)[P~P]CoH]+-complex and its subsequent reactions. The enhanced reactivity of terminal E-1,3-dienes over the corresponding Z-dienes can also be explained on the basis of the ease of formation of this η4-complex in the former case. The lack of reactivity of the X2Co(dppb) (X = Cl, Br) complexes in the presence of Zn/ZnI2 makes the Me3Al-mediated reaction different from the previously reported hydroalkenylation of dienes. Electron-rich phospholanes, bis-oxazolines and N-heterocyclic carbenes appear to be poor ligands for the Co(II)-catalysed hydrovinylation of 1,3-dienes. An extensive survey of chiral ligands reveals that complexes of DIOP, BDDP and Josiphos ligands are quite effective for these reactions even at -45 °C and enantioselectivities in the range of 90-99 % ee can be realized for a variety of 1,3-dienes. Cobalt(II)-complex of an electron-deficient Josiphos ligand is especially active, requiring only <1 mol% catalyst to effect the reactions.
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Affiliation(s)
- Yam N. Timsina
- Department of Chemistry and Biochemistry , The Ohio State University , 100 West 18th Avenue , Columbus , Ohio 43210 , USA . ; Fax: +1 614 292 1685 ; Tel: +1 614 688 3543
| | - Rakesh K. Sharma
- Department of Chemistry and Biochemistry , The Ohio State University , 100 West 18th Avenue , Columbus , Ohio 43210 , USA . ; Fax: +1 614 292 1685 ; Tel: +1 614 688 3543
| | - T. V. RajanBabu
- Department of Chemistry and Biochemistry , The Ohio State University , 100 West 18th Avenue , Columbus , Ohio 43210 , USA . ; Fax: +1 614 292 1685 ; Tel: +1 614 688 3543
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Biswas S, Zhang A, Raya B, RajanBabu TV. Triarylphosphine Ligands with Hemilabile Alkoxy Groups. Ligands for Nickel(II)-Catalyzed Olefin Dimerization Reactions. Hydrovinylation of Vi-nylarenes, 1,3-Dienes, and Cycloisomerization of 1,6-Dienes. Adv Synth Catal 2014; 356:2281-2292. [PMID: 25395919 DOI: 10.1002/adsc.201400237] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Substitution of one of the phenyl groups of triphenylphosphine with a 2-benzyloxy-, 2-benzyloxymethyl- or 2-benzyloxyethyl-phenyl moiety results in a set of simple ligands, which exhibit strikingly different behaviour in various nickel(II)-catalyzed olefin dimerization reactions. Complexes of ligands with 2-benzyloxyphenyl-, 2-benzyloxymethylphenyl-diphenylphosphine (L5 and L6 respectively) are most active for hydrovinylation (HV) of vinylarenes, with the former leading to extensive isomerization of the primary 3-aryl-1-butenes into the conjugated 2-aryl-2-butenes even at -55 °C. However, 2-benzyloxymethyl-substituted ligand L6 is slightly less active, leading up to quantitative yields of the primary products of HV at ambient temperature with no trace of isomerization, thus providing the best option for a practical synthesis of these compounds. In sharp contrast, hydrovinylation of a variety of 1,3-dienes is best catalyzed by nickel(II)-complexes of 2-benzyloxyphenyldiphenylphosphine, L5. The other two ligands, 2-benzyloxymethyl-(L6) and 2-benzyloxyethyl-diphenylphosphine (L7) are much less effective in the HV of 1,3-dienes. Nickel(II)-catalyzed cycloisomerization of 1,6-dienes into methylenecyclopentanes, a reaction mechanistically related to the other hydrovinylation reactions, is also uniquely effected by nickel(II)-complexes of L5, but not of L6 or L7. In an attempt to prepare authentic samples of the methylencyclohexane products, nickel(II)-complexes of N-heterocyclic carbene-ligands were examined. In sharp contrast to the phosphines, which give the methylenecyclopentanes, methylenecyclohexanes are the major products in the (N-heterocyclic carbene)nickel(II)-mediated reactions.
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Affiliation(s)
- Souvagya Biswas
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18 Avenue, Columbus, OHIO 43210, USA ; phone: (001)-614-688-3543
| | - Aibin Zhang
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18 Avenue, Columbus, OHIO 43210, USA ; phone: (001)-614-688-3543
| | - Balaram Raya
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18 Avenue, Columbus, OHIO 43210, USA ; phone: (001)-614-688-3543
| | - T V RajanBabu
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18 Avenue, Columbus, OHIO 43210, USA ; phone: (001)-614-688-3543
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Saini V, Stokes BJ, Sigman MS. Transition-metal-catalyzed laboratory-scale carbon-carbon bond-forming reactions of ethylene. Angew Chem Int Ed Engl 2013; 52:11206-20. [PMID: 24105881 PMCID: PMC3990188 DOI: 10.1002/anie.201303916] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Indexed: 11/07/2022]
Abstract
Ethylene, the simplest alkene, is the most abundantly synthesized organic molecule by volume. It is readily incorporated into transition-metal-catalyzed carbon-carbon bond-forming reactions through migratory insertions into alkylmetal intermediates. Because of its D2h symmetry, only one insertion outcome is possible. This limits byproduct formation and greatly simplifies analysis. As described within this Minireview, many carbon-carbon bond-forming reactions incorporate a molecule (or more) of ethylene at ambient pressure and temperature. In many cases, a useful substituted alkene is incorporated into the product.
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Affiliation(s)
- Vaneet Saini
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, UT 84112 (USA)
| | - Benjamin J. Stokes
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, UT 84112 (USA)
| | - Matthew S. Sigman
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, UT 84112 (USA)
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8
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Conjugate Addition of Organoaluminum Species to Michael Acceptors and Related Processes. TOP ORGANOMETAL CHEM 2012. [DOI: 10.1007/3418_2012_40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
The scope of Ni(II)-catalyzed hydrovinylation has been extended to strained alkenes such as heterobicyclic [2.2.1]heptanes and cylobutenes. Reactions involving the heterobicyclic compounds are rare examples for this class of compounds where the metal-catalyzed C-C bond-forming reactions proceed without a concomitant ring-opening process. While the enantioselectivity in these systems remains modest, hydrovinylation of endo-5,6--bis-benzyloxymethylbicyclo[2.2.1]hept-2-ene gives excellent yield (>90%) of the product with one of the highest enantioselectivities (95-99% ee) reported for a C-C bond-forming reaction of norbornenes.
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Affiliation(s)
- Wang Liu
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
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10
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Gao F, Lee Y, Mandai K, Hoveyda AH. Quaternary carbon stereogenic centers through copper-catalyzed enantioselective allylic substitutions with readily accessible aryl- or heteroaryllithium reagents and aluminum chlorides. Angew Chem Int Ed Engl 2010; 49:8370-4. [PMID: 20886589 PMCID: PMC3498987 DOI: 10.1002/anie.201005124] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Fang Gao
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467 (USA), Fax: (1) 617-552-1442
| | - Yunmi Lee
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467 (USA), Fax: (1) 617-552-1442
| | - Kyoko Mandai
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467 (USA), Fax: (1) 617-552-1442
| | - Amir H. Hoveyda
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467 (USA), Fax: (1) 617-552-1442
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11
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Gao F, McGrath KP, Lee Y, Hoveyda AH. Synthesis of quaternary carbon stereogenic centers through enantioselective Cu-catalyzed allylic substitutions with vinylaluminum reagents. J Am Chem Soc 2010; 132:14315-20. [PMID: 20860365 PMCID: PMC2951504 DOI: 10.1021/ja106829k] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Catalytic enantioselective allylic substitution (EAS) reactions, which involve the use of alkyl- or aryl-substituted vinylaluminum reagents and afford 1,4-dienes containing a quaternary carbon stereogenic center at their C-3 site, are disclosed. The C-C bond-forming transformations are promoted by 0.5-2.5 mol % of sulfonate bearing chiral bidentate N-heterocyclic carbene (NHC) complexes, furnishing the desired products efficiently (66-97% yield of isolated products) and in high site (>98% S(N)2')- and enantioselectivity [up to 99:1 enantiomer ratio (er)]. To the best of our knowledge, the present report puts forward the first cases of allylic substitution reactions that result in the generation of all-carbon quaternary stereogenic centers through the addition of a vinyl unit. The aryl- and vinyl-substituted vinylaluminum reagents, which cannot be prepared in high efficiency through direct reaction with diisobutylaluminum hydride, are accessed through a recently introduced Ni-catalyzed reaction of the corresponding terminal alkynes with the same inexpensive metal-hydride agent. Sequential Ni-catalyzed hydrometalations and Cu-catalyzed C-C bond-forming reactions allow for efficient and selective synthesis of a range of enantiomerically enriched EAS products, which cannot be accessed by previously disclosed strategies (due to inefficient vinylmetal synthesis or low reactivity and/or selectivity with Si-substituted derivatives). The utility of the protocols developed is demonstrated through a concise enantioselective synthesis of natural product bakuchiol.
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Affiliation(s)
- Fang Gao
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467
| | - Kevin P. McGrath
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467
| | - Yunmi Lee
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467
| | - Amir H. Hoveyda
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467
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Lim HJ, Smith CR, RajanBabu TV. Facile Pd(II)- and Ni(II)-catalyzed isomerization of terminal alkenes into 2-alkenes. J Org Chem 2009; 74:4565-72. [PMID: 19441793 PMCID: PMC2715430 DOI: 10.1021/jo900180p] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mono- and 2,2'-disubstituted terminal alkenes can be isomerized into the more stable internal (Z)- and (E)-alkenes by treating them with catalytic amounts of [(allyl)PdCl](2) or [(allyl)NiBr](2), a triarylphosphine, and silver triflate at room temperature. The isomeric ratio (E:Z) depends on the alkenes, the E-isomer being the major one. The reaction is tolerant to a wide variety of functional groups including other reactive olefins. Unlike the more reactive Ir catalysts, monosubstituted alkenes give almost exclusively the 2-alkenes. Direct comparison to two of the best-known catalysts for this process {[Ir(PCy(3))(3)](+)[BPh(4)](-) and Grubbs generation II metathesis catalyst} is also described.
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Affiliation(s)
- Hwan Jung Lim
- Department of Chemistry, The Ohio State University, 100 W. 18 Avenue, Columbus, Ohio 43210
| | - Craig R. Smith
- Department of Chemistry, The Ohio State University, 100 W. 18 Avenue, Columbus, Ohio 43210
| | - T. V. RajanBabu
- Department of Chemistry, The Ohio State University, 100 W. 18 Avenue, Columbus, Ohio 43210
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