A pineno-salen type catalyst for the enantioselective Nozaki–Hiyama–Kishi reaction
摘要:
A new class of pineno-salen type ligands 10, 11, 17, 20, 23, and 24 has been developed. The catalyst formed from chromium(II)-10 promotes the enantioselective Nozaki-Hiyama-Kishi allylation of alkyl and aryl aldehydes using allyl bromide. Notably, the asymmetric addition of vinyl halide to benzaldehyde was achieved with 24% ee. (C) 2012 Elsevier Ltd. All rights reserved.
Several new chiral bipyridyldiol ligands that promote the chromium-catalyzedenantioselective addition of allylic halides to aldehydes in up to 99% ee were synthesized. The chromium-catalyzed allylation of aldehydes using ligands 4 and 4a in the presence of chromium(III) chloride and allyl chloride provided the highest enantioselectivity.
A Chiral Bipyridyl Alcohol for Catalytic Enantioselective Nozaki-Hiyama-Kishi Allylation of Aldehydes and Ketones
作者:Rui-Yu Chen、Attrimuni P. Dhondge、Gene-Hsian Lee、Chinpiao Chen
DOI:10.1002/adsc.201400945
日期:2015.3.23
Nozaki–Hiyama–Kishi (NHK) allylation of aldehydes and ketones with allylic halides. The allylation of various aromatic, α,β‐unsaturated, and aliphatic aldehydes and ketones produces the desired homoallylic alcohols in satisfactory yields (up to 98%) and high enantioselectivities (up to 99% ee). The present method can be applied widely and affords an efficient means of obtaining chiral homoallylic alcohols.