N-Boc-aminals as easily accessible precursors for less accessible N-Boc-imines: facile synthesis of optically active propargylamine derivatives using Mannich-type reactions
We developed a facile and practical synthesis of N-Boc-aminals, which can be used as precursors for less accessible N-Boc-imines. Aminals were obtained via simple dehydration condensation reactions of t-butyl carbamate (BocNH2) and various aldehydes in acetic anhydride, followed by filtration and washing with hexane. The obtained N-Boc-alkynylaminals could be successfully applied in enantioselective
Abstract A synthesis of N‐protected β‐aminomalonates starting from α‐amidosulfones under very mild and simple reaction conditions is described. Treatment of the sulfones with malonate esters in the presence of 2.5 equivalents of potassium carbonate affords the desired products in good yield. A variety of N‐Z and N‐Boc protected aliphatic and aromatic α‐aminosulfones and malonate esters have been successfully
摘要描述了在非常温和和简单的反应条件下,以 α-酰胺砜为原料合成 N 保护的 β-氨基丙二酸酯。在2.5当量碳酸钾存在下用丙二酸酯处理砜以良好收率提供所需产物。多种 N-Z 和 N-Boc 保护的脂肪族和芳香族 α-氨基砜和丙二酸酯已成功用作起始材料。水解伴随着 N 保护的 β-氨基丙二酸酯的脱羧,为获得外消旋 β-氨基酸提供了便利。