肽基烯烃肽模拟物用作生物活性化合物或用作其他肽基等排体的中间体。C=C 键的 N 端侧可以很容易地从 α-氨基酸以光学纯的形式制备。以光学纯形式合成 C 端结构单元更具挑战性。我们开发了一种化学酶立体选择性方法,用于通过各种反应组装成肽基烯烃的光学活性 C 端结构单元。它们包括亲电子醛和亲核砜、鏻盐、膦酸盐和二硒化物。前手性二酯到相应羟基酯的关键酶水解引入了光学活性。随后化学反应的顺序,无论是保护-水解-功能化还是功能化-水解-保护,
Epoxidation of Peptidyl Olefin Isosteres. Stereochemical Induction Effect of Chiral Centers at Four Adjacent Cα Positions
摘要:
Four tripeptidyl olefin isosteres were prepared, each of which contains a single chiral center derived from the bulky amino acid phenylalanine at positions corresponding to the P-2-P'(2) positions of a protease substrate. The effect of these chiral centers on the stereochemical outcome of mCPBA epoxidation of the olefin functionality was studied. A chiral center at P-2 or P'(2) position has no significant effect, and the P'(1) position exerts a small stereoselectivity. A chiral center at the P-1 position, on the other hand, has a profound chiral induction effect on the epoxidation reaction. (C) 2000 Elsevier Science Ltd. All rights reserved.