异丙氧基二异丁基铝：关于溶剂对环酮还原反应速率和立体选择性影响的研究

Al-isopropoxydiisobutylalane: a study of the effect of solvent on the rate and stereoselectivity of cyclic ketone reduction.

作者信息

Bahia Perdip S, Jones Matthew A, Snaith John S

机构信息

School of Chemistry, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.

出版信息

J Org Chem. 2004 Dec 24;69(26):9289-91. doi: 10.1021/jo049300f.

DOI:10.1021/jo049300f

PMID:15609968

Abstract

The effect of solvent on the rate and stereoselectivity of cyclic ketone reduction by Al-isopropoxydiisobutylalane (DIBA(i)OPr) has been investigated. In dichloromethane, DIBA(i)OPr behaves as a bulky reducing agent, approaching the carbonyl group along an equatorial trajectory to produce the axial alcohol with >10:1 stereoselectivity. In sharp contrast, reduction in toluene gives the complementary outcome, affording the thermodynamically more stable isomer with >99:1 stereoselectivity.

摘要

研究了溶剂对异丙氧基二异丁基铝（DIBA(i)OPr）还原环酮的速率和立体选择性的影响。在二氯甲烷中，DIBA(i)OPr表现为一种体积较大的还原剂，沿赤道轨迹接近羰基，以>10:1的立体选择性生成轴向醇。与之形成鲜明对比的是，在甲苯中进行还原则得到相反的结果，以>99:1的立体选择性提供热力学上更稳定的异构体。