motifs in organocatalysis, whereas efficient 1,3‐diamine‐derived organocatalysts are very rare. Herein we report a highly efficient camphor‐1,3‐diamine‐derived squaramideorganocatalyst. Its catalytic activity in Michaeladditions of 1,3‐dicarbonyl nucleophiles to trans‐β‐nitrostyrene derivatives provides excellent enantioselectivities (up to >99% ee).
Asymmetric Michael addition reactions catalyzed by calix[4]thiourea cyclohexanediamine derivatives
作者:Zheng-Yi Li、Hong-Xiao Tong、Yuan Chen、Hong-Kui Su、Tangxin Xiao、Xiao-Qiang Sun、Leyong Wang
DOI:10.3762/bjoc.14.164
日期:——
rim-functionalized calix[4]thiourea cyclohexanediamine derivatives have been designed, synthesized and used as catalysts for enantioselective Michael addition reactions between nitroolefins and acetylacetone. The optimal catalyst 2 with a mono-thiourea group exhibited good performance in the presence of water/toluene (v/v = 1:2). Under the optimal reaction conditions, high yields of up to 99% and moderate
Highly enantioselectiveMichaelreactions between acetylacetone and trans-β-nitroolefins are achieved by a novel ferrocenophane-based tertiary amine-thiourea organocatalyst to provide the corresponding products in good to excellent yields (up to 95%) and enantioselectivities (up to 99% ee).
efficient method was developed to synthesize ferrocene-based bifunctionalamine–thioureasbearingmultiplehydrogen-bondingdonors. Asymmetric Michaeladdition of acetylacetone to nitroolefins catalyzed by these novel bifunctionalcatalysts affords the Michael adducts in high yield and moderate to excellent enantioselectivities. Multiplehydrogen-bonds play an important role in accelerating the reaction.