One-pot syntheses of sulfinates, sulfinamides, and thiosulfinates by O-, N-, and S-sulfinylations of alcohols, amines, and thiols with p-toluenesulfinic acid in the presence of various activating reagents, phenyl phosphorodichloridate (1), diphenyl phosphoro-chloridate (2), triphenylphosphine N-chlorosuccinimide (NCS) (3), and 3-(phthalimidoxy)-1, 2-benzoisothiazole 1, 1-dioxide (4), were investigated. All of these reagents were reasonably effective for O-and S-sulfinylation, but ineffective for N-sulfinylation. Among them, the reagents 1 and 2 were slightly more efficient than the others.
4-Dimethylaminopyridine-catalyzed reaction of mixed carbonates 3 with N-protected amino acids 4 gave the corresponding active esters 5-9, from which dipeptides 11-18 were synthesized by aminolysis with amino acids 10.
Metal-free decarboxylative C(sp3)–C(sp3) bond formation for the synthesis of unnatural amino acids and peptides via convergent paired electrolysis enabled radical–radical cross-coupling
Herein, we present the first metal-free decarboxylative C(sp3)–C(sp3) cross-coupling of glycine derivatives with redox-active esters through highly atom and energy economical convergent paired electrolysis enabled radical–radical cross-coupling. Under mild and scalable conditions, various α-alkylated unnatural α-amino acids were prepared efficiently from readily available starting materials. The key