描述了使用Pd(OAc)2作为催化剂,将α-氨基酸底物的未活化β-亚甲基C(sp 3)H键与多种烷基碘进行烷基化。发现添加NaOCN和4-Cl-C 6 H 4 SO 2 NH 2对于该转化成功至关重要。该反应与各种各样的官能团相容,并且以非对映选择性高的方式进行。此外,通过顺序C(sp 3)制备了各种β,β-杂二烷基和β-烷基-β-芳基-α-氨基酸丙氨酸衍生底物的H功能化,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。
Late-stage C(sp<sup>2</sup>)–H and C(sp<sup>3</sup>)–H glycosylation of <i>C</i>-aryl/alkyl glycopeptides: mechanistic insights and fluorescence labeling
C(sp3)–H and C(sp2)–H glycosylations of structurally complex amino acids and peptides were accomplished through the assistance of triazole peptide-isosteres. The palladium-catalyzed peptide–saccharide conjugation provided modular access to structurally complex C-alkyl glycoamino acids, glycopeptides and C-aryl glycosides, while enabling the assembly of fluorescent-labeled glycoamino acids. The C–H