β-Di-substituted α-amino acids (AAs) contain adjacent carbon stereogenic centers and pose considerable synthetic challenge. Complementary to the conventional synthesis strategies based on the transformation of existing functional groups, we envisioned these molecules could be quickly accessed via selective functionalization of sp3 hybridized C-H bonds on the side chains of common α-AA precursors. We report a readily applicable method to prepare β-alkynyl α-amino acids via Pd-catalyzed diastereoselective C(sp3)-H alkynylation of common α-amino acids precursors with acetylene bromide.
β-二取代
α-氨基酸(
AAs)含有相邻的
碳立体中心,给合成带来了相当大的挑战。作为对基于现有官能团转化的传统合成策略的补充,我们设想可以通过对常见 α-
AA 前体侧链上的 sp3 杂化 C-H 键进行选择性官能化来快速获得这些分子。我们报告了一种通过
钯催化常见 α-
氨基酸前体与
溴化
乙炔的非对映选择性 C(sp3)-H 烷炔化反应制备 β- 烷炔基 α-
氨基酸的简便方法。