Catalytic asymmetric allylation using a chiral (acyloxy)borane complex as a versatile Lewis acid catalyst

• Published in: Journal of the American Chemical Society Vol. 115; no. 24; pp. 11490 - 11495
• Main Authors: Ishihara, Kazuaki, Mouri, Makoto, Gao, Qingzhi, Maruyama, Tohru, Furuta, Kyoji, Yamamoto, Hisashi
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 01.12.1993; Amer Chemical Soc
• Subjects: Catalysis; Catalytic reactions; Chemistry; Chemistry, Multidisciplinary; Exact sciences and technology; General and physical chemistry; Physical Sciences; Science & Technology; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; TARTRATE; ALLYLBORATION; HOMOALLYLIC ALCOHOLS; ALDOL REACTIONS; ALDEHYDES; ACYLOXYBORANE; ORGANOBORANES; Five membered ring; Catalytic reaction; Enantioselectivity; Silicon Organic compounds; Organic silane; Chiral compound; Aldehyde; Experimental study; Asymmetric catalysis; Diastereoselectivity; Allylation; Oxygen boron heterocycle; Catalyst
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja00077a054

In the presence of 20 mol % of a chiral (acyloxy)borane (CAB) complex prepared from (2R,3R)-2-O-(2,6-diisopropoxybenzoyl)tartaric acid and borane-tetrahydrofuran, various allyltrimethylsilanes react with achiral aldehydes to afford the corresponding homoallylic alcohols in good yields with high diastereo- and enantioselectivities. Furthermore, the reactivity of allylation can be improved without reducing the enantioselelctivity by using 10-20 mol % of the CAB complex prepared from 3,5-bis(trifluoromethyl)phenylboronic acid and chiral tartaric acid derivative. The observed selectivities and re-face attack of nucleophiles on the carbonyl carbons of aldehydes imply that the extended transition-state model is applicable.