Nickel‐Catalyzed Asymmetric Reductive Arylalkylation of Unactivated Alkenes

• Published in: Angewandte Chemie International Edition Vol. 58; no. 20; pp. 6722 - 6726
• Main Authors: Jin, Youxiang, Wang, Chuan
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 13.05.2019; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Alkenes; annulations; Aromatic compounds; asymmetric catalysis; Benzene; Bromides; Catalysis; Chemistry; Chemistry, Multidisciplinary; Cyclic compounds; Nickel; Organometallic compounds; Physical Sciences; Science & Technology; synthetic methods; Zinc; nickel; STYRENES; asymmetric catalysis; DIARYLATION; alkenes; ALKYL-HALIDES; annulations; CONSTRUCTION; BONDS; OLEFINS; DICARBOFUNCTIONALIZATION; synthetic methods; CYCLIZATION
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201901067

Reported is an asymmetric reductive dicarbofunctionalization of unactivated alkenes. Under the catalysis of a Ni/BOX system, various aryl bromides, incorporating a pendant olefinic unit, were successfully reacted with an array of primary alkyl bromides in the presence of Zn as a reductant, furnishing a series of benzene‐fused cyclic compounds bearing a quaternary stereocenter in high enantioselectivities. Notably, this reaction avoids the use of pregenerated organometallics and demonstrates high tolerance of sensitive functionalities. The preliminary mechanistic investigations reveal that this Ni‐catalyzed reaction proceeds as a cascade consisting of migratory insertion and cross‐coupling with a nickel(I)‐mediated intramolecular 5‐exo cyclization as the enantiodetermining step. Ring fusion: A nickel‐catalyzed asymmetric arylalkylation of tethered unactivated alkenes provides benzene‐fused cyclic compounds containing a quaternary stereocenter in a highly enantioselective fashion. The generation of organometallics is not necessary, and the functional‐group tolerance is high.