NHC‐Ni(0) Catalyzed Diastereodivergent Hydroacylative Enyne Cyclization: Synthesis of Heterocycles bearing γ‐Enone

• Published in: Advanced synthesis & catalysis Vol. 362; no. 19; pp. 4164 - 4172
• Main Authors: Yong, Xuefeng, Ng, Elvis Wang Hei, Zhen, Zibo, Lin, Xiulian, Gao, Weiwei, Ho, Chun‐Yu
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 06.10.2020; Wiley Subscription Services, Inc
• Subjects: Acylation; Aldehydes; Chemical synthesis; Chemistry; Chemistry, Applied; Chemistry, Organic; Heterocycles; Insertion; N-heterocyclic carbenes; Nickel; Olefination; Physical Sciences; Science & Technology; Selectivity; Stereoselectivity; Heterocycles; ALPHA-OLEFINS; STYRENES; CARBENE; 1,6-ENYNES; Olefination; UNSATURATED-HYDROCARBONS; Insertion; ALDEHYDES; 2+2+2 CYCLOADDITION; LACTONES; CROSS-HYDROALKENYLATION; Nickel; Acylation; N-heterocyclic carbenes
• ISSN: 1615-4150; 1615-4169
• DOI: 10.1002/adsc.202000718

NHC‐Nickel(0) catalyzed 1,3‐ and 1,4‐diastereodivergent hydroacylative heteroenyne cyclization with aldehydes was achieved (Syn‐:Anti‐, switchable from up to 1:99 to 98:2). Both sets of heterocyclic diastereomers are accessible via this route, with a high γ‐:α‐enone structure ratio. Preliminary DFT investigations indicated that the manipulation of the N‐substituent exerts a direct influence on the diastereoselectivity of NHC‐nickelacyclopentene formation. The energy differences associated with the endocyclic bond angle (C−Z−C) changes noted in the calculations, might possibly account for the broad scope and high diastereodivergent selectivity observed.