Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
J Am Chem Soc. 2010 Apr 14;132(14):5030-2. doi: 10.1021/ja101256v.
A new thiourea catalyst is reported for the enantioselective cationic polycyclization of hydroxylactams. Both the yield and enantioselectivity of this transformation were found to vary strongly with the identity of a single aromatic residue on a common catalyst framework, with more expansive and polarizable arenes proving optimal. Evidence is presented for a mechanism in which stabilizing cation-pi interactions are a principal determinant of enantioselectivity.
一种新型硫脲催化剂被报道用于羟基内酰胺的对映选择性阳离子多环化反应。该转化的产率和对映选择性都强烈地依赖于通用催化剂骨架上一个单个芳基残基的身份,更扩展和极化的芳基证明是最佳的。提出了一种机制的证据,其中稳定的阳离子-π相互作用是对映选择性的主要决定因素。