Cross‐Coupling Reaction of Alkenyl Sulfoximines and Alkenyl Aminosulfoxonium Salts with Organozincs by Dual Nickel Catalysis and Lewis Acid Promotion

• Published in: Chemistry : a European journal Vol. 25; no. 35; pp. 8371 - 8386
• Main Authors: Erdelmeier, Irene, Bülow, Gerd, Woo, Chang‐Wan, Decker, Jürgen, Raabe, Gerhard, Gais, Hans‐Joachim
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 21.06.2019; Wiley Subscription Services, Inc
• Subjects: Acceleration; Alcohols; Alkenes; alkenyl sulfoximines; Catalysis; Chemical industry; Chemistry; Chemistry, Multidisciplinary; Coupling; cross-coupling; Diethyl ether; Lewis acid; Magnetic resonance spectroscopy; Nickel; NMR; NMR spectroscopy; Nuclear magnetic resonance; Physical Sciences; Promotion; Reagents; salt promotion; Salts; Science & Technology; Selectivity; Stereoselectivity; Zinc; nickel; CRYSTAL-STRUCTURE ANALYSIS; ENANTIOSELECTIVE SYNTHESIS; alkenyl sulfoximines; HOMOALLYLIC ALCOHOLS; catalysis; HORNER-WADSWORTH-EMMONS; cross-coupling; ASYMMETRIC WITTIG REACTIONS; STEREOSELECTIVE-SYNTHESIS; salt promotion; ALLYLIC SULFOXIMINES; CHIRAL ARSONIUM YLIDES; GRIGNARD-REAGENTS; CONJUGATE ADDITION
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201901163

In this article, the cross‐coupling reaction (CCR) of exocyclic, axially chiral, and acyclic alkenyl (N‐methyl)sulfoximines with alkyl‐ and arylzincs is described. The CCR generally requires dual Ni catalysis and MgBr2 promotion, which is effective in diethyl ether but not in THF. NMR spectroscopy revealed a complexation of alkenyl sulfoximines by MgBr2 in diethyl ether, which suggests an acceleration of the oxidative addition through nucleofugal activation. The CCR of alkenyl sulfoximines generally proceeds in the presence of Ni(dppp)Cl2 as a precatalyst and MgBr2 with alkyl‐ and arylzincs with a high degree of stereoretention at the C and the S atom. CCR of axially chiral alkenyl sulfoximines with Ni(PPh3)2Cl2 as a precatalyst and ZnPh2 does not require salt promotion and is stereoretentive. The reaction with Zn(CH2SiMe3)2, however, demands salt promotion and is not stereoretentive. CCR of axially chiral α‐methylated alkenyl sulfoximines afforded persubstituted axially chiral alkenes with high selectivity. Alkenyl (N‐triflyl)sulfoximines engage in a stereoretentive CCR with Grignard reagents and Ni(PPh3)2Cl2. Ni‐Catalyzed and MgBr2‐promoted CCR of E‐configured acyclic alkenyl sulfoximines and aminosulfoxonium salts with ZnPh2 and Zn(CH2SiMe3)2 is stereoretentive with Ni(dppp)Cl2 and Ni(PPh3)2Cl2. CCRs of acyclic alkenyl sulfoximines and alkenyl aminosulfoxonium salts, carrying a methyl group at the α position, take a different course and give alkenyl sulfinamides under stereoretention at the S and C atom. CCR of acyclic, exocyclic, and axially chiral alkenyl sulfoximines has been successfully applied to the stereoselective synthesis of homoallylic alcohols, exocyclic alkenes, and axially chiral alkenes, respectively. Alkenyl sulfoximines undergo a dual Ni‐catalyzed and MgBr2‐promoted stereoretentive cross‐coupling reaction (CCR) with organozincs (see Scheme). Salt promotion is due to a coordination and activation of the sulfonimidoyl group. CCR of alkenyl sulfoximines together with an inverse Peterson olefination of the corresponding ketones with chiral lithiomethyl sulfoximines are the key steps of a stereoselective synthesis of exocyclic and axially chiral alkenes.