&agr;,&bgr;-Unsaturated amides and esters are converted to &agr;,&bgr;-substituted amino amides, esters, and acids. An &agr;,&bgr;unsaturated amide or ester is first converted to an &agr;,&bgr;-hydroxysulfonamide or hydroxycarbamate amide or ester using an osmium-catalyzed aminohydroxylation. The &agr;,&bgr;-hydroxysulfonamide or hydroxycarbamate amides or esters is then cyclodehydrated to produce a &agr;,&bgr;-N-sulfonyl- or the &agr;,&bgr;-N-carbamoylaziridine amide or ester. The ring of aziridine intermediate is then nucleophilically opened in a regioselective manner with a variety of nucleophiles to give the $g(&agr;,&bgr;-substituted amino- amides or esters. Preferred nucleophiles include sulfur, oxygen, carbon, and nitrogen nucleophiles.
不饱和酰胺和酯可转化为α,β-取代
氨基酰胺、酯和酸。首先使用
锇催化的
氨羟化反应将α,β-不饱和酰胺或酯转化为α,β-羟基磺酰胺或羟基
氨基甲酸酯。然后,α,β-羟基磺酰胺或羟基
氨基甲酸酯环脱
水,产生α,β-N-磺酰基或α,β-N-
氨甲酰环氧
丙烷酰胺或酯。接着,通过亲核取代反应,以多种亲核试剂选择性地开放
环丙烷中间体的环,得到α,β-取代
氨基酰胺或酯。首选的亲核试剂包括
硫、氧、碳和氮亲核试剂。