作者:Kenichi Michigami、Tatsuhiko Sakaguchi、Yoshiji Takemoto
DOI:10.1021/acscatal.9b03894
日期:2020.1.3
Alkane-gem-diboronic acids have emerged as versatile organoboron catalysts for dehydrative amidation of α-amino acids. A phenol-substituted multiboron catalyst with a B–C–B structure outperformed simple arylboronic acids in the condensation of α-amino acids with suppressed epimerization of electrophiles. gem-diboronic acid catalysis were compatible with various O, N, and S-functionalized α-amino acids bearing N-protecting
烷烃-宝石-二硼酸已经成为用于α-氨基酸脱水酰胺化的通用有机硼催化剂。具有α–C–B结构的苯酚取代的多硼催化剂在α-氨基酸的缩合和亲电异构体的抑制作用方面优于简单的芳基硼酸。宝石-二硼酸催化与各种带有N-保护基团的O,N和S-官能化的α-氨基酸兼容,这些保护基团包括肽合成中常用的氨基甲酸酯(Boc,Cbz,Fmoc)。ñ-三氟乙酰基保护作用使室温下空前的催化脱水肽合成成为可能。初步的机理研究表明,宝石-二硼酸的羧酸盐结合性质与芳基硼酸对羧酸的活化作用正交。宝石-二硼酸的独特反应性将为轻度催化肽缩合打开前景。