Department of Chemistry, Zhejiang University, Hangzhou 310027 (China).
Angew Chem Int Ed Engl. 2014 Oct 27;53(44):11950-4. doi: 10.1002/anie.201407848. Epub 2014 Sep 11.
The alkylation of unactivated β-methylene C(sp(3))-H bonds of α-amino acid substrates with a broad range of alkyl iodides using Pd(OAc)2 as the catalyst is described. The addition of NaOCN and 4-Cl-C6H4SO2NH2 was found to be crucial for the success of this transformation. The reaction is compatible with a diverse array of functional groups and proceeds with high diastereoselectivity. Furthermore, various β,β-hetero-dialkyl- and β-alkyl-β-aryl-α-amino acids were prepared by sequential C(sp(3))-H functionalization of an alanine-derived substrate, thus providing a versatile strategy for the stereoselective synthesis of unnatural β-disubstituted α-amino acids.
描述了使用 Pd(OAc)2 作为催化剂，用广泛的烷基碘对α-氨基酸底物的未活化的β-亚甲基 C(sp(3))-H 键进行烷基化。发现添加 NaOCN 和 4-Cl-C6H4SO2NH2 对于此转化的成功至关重要。该反应与各种官能团兼容，并具有高的非对映选择性。此外，通过对丙氨酸衍生的底物进行连续的 C(sp(3))-H 官能化，制备了各种β，β-杂二烷基-β-烷基-β-芳基-α-氨基酸，从而为非天然β-二取代α-氨基酸的立体选择性合成提供了一种通用策略。
