Preparation of the Zinc Enolate Equivalent of Amides by Zinciomethylation of Isocyanates: Catalytic Asymmetric Reformatsky-Type Reaction
作者:Seijiro Matsubara、Ryosuke Haraguchi
DOI:10.1055/s-0034-1378514
日期:——
an activator, leads to a catalytic asymmetric Reformatsky-type reaction. Bis(iodozincio)methane [CH2(ZnI)2] transforms isocyanates (R–N=C=O) into the enolate equivalent of amides via zinciomethylation. The reactivity of the enolate equivalent as a nucleophile toward aldehydes depends on the R group of the isocyanate. For the enolate equivalent formed from phenyl isocyanate, the addition of a catalytic
摘要 双(碘并甲烷)甲烷[CH 2(ZnI)2 ]通过锌甲基化将异氰酸酯(RN = C = O)转化为酰胺的烯醇式当量。作为亲核体的烯醇化物等效物对醛的反应性取决于异氰酸酯的R基团。对于由异氰酸苯酯形成的烯醇盐当量,加入催化量的光学活性氨基醇(作为活化剂)会导致催化不对称的Reformatsky型反应。 双(碘并甲烷)甲烷[CH 2(ZnI)2 ]通过锌甲基化将异氰酸酯(RN = C = O)转化为酰胺的烯醇式当量。作为亲核体的烯醇化物等效物对醛的反应性取决于异氰酸酯的R基团。对于由异氰酸苯酯形成的烯醇盐当量,加入催化量的光学活性氨基醇(作为活化剂)会导致催化不对称的Reformatsky型反应。
Synthesis of some new 5-substituted-3-phenyl-4-thioxo-2-thiazolidinones and their fused thiopyrano[2,3-<i>d</i>]thiazole derivatives
作者:Mohamed Ahmed Badawy、Nadia Hanafy Metwally、Doha Samir Okpy
DOI:10.1080/17415993.2015.1065405
日期:2015.9.3
5-arylmethylene-3-phenyl-4-thioxo-2-thiazolidinone derivatives have been synthesized by condensation of ω-(4-formylphenoxy)acetophenone derivatives with 3-phenyl-4-thioxo-2-thiazolidinone, in good yields. The cycloaddition of the newly synthesized compounds to N-arylmaleimides, ethyl acrylate and ω-nitrostyrene has been studied. Under thermal reaction conditions [4+2] cycloaddition proceeds with complete site-