Small Change, Big Impact: Reversal of Diastereoselection in Cuprate Conjugate Additions to α,β-Unsaturated Lactams and Identification of a Competing Mechanism
作者:Stephen W. Wright、Chulho Choi、Yu Kawamata、Phil S. Baran
DOI:10.1021/acs.joc.2c02993
日期:——
reactant is shown to cause a change in reaction mechanisms. Conjugate addition of organocopper reagents to bicyclic α,β-unsaturated lactams derived from pyroglutaminol is determined by the nature of the aminal group. Aminals derived from aldehydes give anti addition; those from ketones give syn addition. Divergence in diastereoselection occurs because the substrates react by different mechanisms, ultimately
反应物看似微小的变化会导致反应机制发生变化。有机铜试剂与焦谷氨酰胺衍生的双环 α,β-不饱和内酰胺的共轭加成取决于氨基的性质。来自醛的缩醛胺具有反加成作用;来自酮的那些产生顺式加成。非对映选择的差异发生是因为底物通过不同的机制反应,最终是由于氨氮的金字塔化存在微小但显着的差异。