期刊
JOURNAL OF ORGANIC CHEMISTRY
卷 73, 期 1, 页码 168-176出版社
AMER CHEMICAL SOC
DOI: 10.1021/jo701943x
关键词
-
[GRAPHICS] A facile and practical approach to preparation of enantiopure N-(ferrocenylmethyl)azetidin-2-yl(diphenyl)methanol was developed from cheap and easily available L-(+)-methionine. Synthetic highlights include the three-step, one-pot construction of the chiral azetidine ring and the development of an improved one-step procedure for the synthesis of the key intermediate L-2-amino-4-bromobutanoic acid. Enantiopure N-(ferrocenylmethyl)azetidin-2-yl(diphenyl)methanol was evaluated for catalytic asymmetric addition of organozinc reagents to aldehydes. The asymmetric ethylation, methylation, arylation, and alkynylation of aldehydes achieved enantioselectivity of up to 98.4%, 94.1%, 99.0%, and 84.6% ee, respectively, in the presence of a catalytic amount of chiral N-(ferrocenylmethyl)azetidin-2-yl(diphenyl)methanol. Our results demonstrated further that the four-membered heterocycle-based backbone was a good potential chiral unit for the catalytic asymmetric induction reaction, and the hindrance of the bulky ferrocenyl group, compared to a phenyl group, played an important role in the enantioselectivities. A possible transition for the catalytic asymmetric addition has been proposed on the basis of the crystal structure of the chiral ligand 3b including two HOAc molecules and previous studies.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据