理解β-烷氧基甲基酮硼醛醇反应中远程不对称诱导的起源。

Understanding the origins of remote asymmetric induction in the boron aldol reactions of beta-alkoxy methyl ketones.

作者信息

Paton Robert S, Goodman Jonathan M

机构信息

Unilever Centre for Molecular Science Informatics, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.

出版信息

Org Lett. 2006 Sep 14;8(19):4299-302. doi: 10.1021/ol061671q.

DOI:10.1021/ol061671q

PMID:16956211

Abstract

We report theoretical studies into the remote 1,5-stereoinduction shown by certain types of beta-alkoxy methyl ketones in boron-mediated aldol reactions with achiral aldehydes. For a range of common alkoxy groups, our calculations are in excellent agreement with experimentally observed diastereoselectivities. In the aldol transition structures, a stabilizing hydrogen bond between the alkoxy oxygen and formyl proton leads to preferential formation of the 1,5-adduct, by minimizing steric interactions between the beta-alkyl group and one of the ligands on boron.

摘要

我们报告了关于某些类型的β-烷氧基甲基酮在硼介导的与非手性醛的羟醛反应中所表现出的远程1,5-立体诱导的理论研究。对于一系列常见的烷氧基，我们的计算结果与实验观察到的非对映选择性非常吻合。在羟醛过渡结构中，烷氧基氧与甲酰基质子之间的稳定氢键通过最小化β-烷基与硼上的一个配体之间的空间相互作用，导致1,5-加合物的优先形成。