Chiral γ‐Lactams by Enantioselective Palladium(0)‐Catalyzed Cyclopropane Functionalizations
作者:Julia Pedroni、Nicolai Cramer
DOI:10.1002/anie.201505916
日期:2015.9.28
palladium(0)‐catalyzed CH functionalizations involving the formation of C(sp3)C(sp3) bonds of saturated heterocycles are very scarce. The presented strategy yields cyclopropane‐fused γ‐lactams from chloroacetamide substrates. A bulky Taddol phosphonite ligand in combination with adamantane‐1‐carboxylic acid as a cocatalyst provides the γ‐lactams in excellent yields and enantioselectivities.
与吡咯烷融合的环丙烷是在许多市售药物和开发候选物中发现的重要结构特征。通常,它们的合成涉及二氢吡咯前体的环丙烷化。本文报道了一种补充方法,该方法采用钯(0)催化的非手性环丙烷的CH官能化,以对映选择性的方式封闭吡咯烷环。与芳基-芳基偶联相反,钯(0)催化的CH官能化涉及C(sp 3)C(sp 3的形成)饱和杂环的键非常稀少。提出的策略从氯乙酰胺底物产生环丙烷融合的γ-内酰胺。笨重的Taddol亚膦酸酯配体与金刚烷-1-羧酸作为助催化剂结合使用时,γ-内酰胺的收率和对映选择性都非常好。