Department of Chemistry, University of Calcutta, University College of Science, 92, A. P. C. Road, Kolkata-700009, India.
J Org Chem. 2012 Nov 16;77(22):10441-9. doi: 10.1021/jo301796r. Epub 2012 Oct 31.
CeCl(3)·7H(2)O is found as an efficient catalyst for new intermolecular domino reactions of three-, four- and seven-component assemblies of common precursors under benign reaction conditions. Generation of enaminioesters from β-keto esters and primary amines, activation of their allylic sp(3) C-H, vinylic sp(2) C-H and N-H bonds, multi C-C and C-N bond-forming cascade cyclization with 1,2-diketones and subsequent side-chain alkylation have been developed to construct functionalized pentasubstituted pyrroles and their chiral analogues. The scope of the domino reaction is successfully explored toward synthesis of highly aryl-substituted pyrroles, pentasubstituted pyrroles bearing C2-olefinic side-chain and spiro-2-pyrrolinones and their chiral analogues via unusual side-chain amination, elimination and ring contraction. The new domino reaction is operationally simple, robust, substrate specific, selective and high yielding.
CeCl(3)·7H(2)O 是一种高效的催化剂，可在温和的反应条件下促进常见前体的三、四和七组分混合物的新型分子间多米诺反应。通过烯胺酯从β-酮酯和伯胺生成，激活它们的烯丙基 sp(3) C-H、乙烯基 sp(2) C-H 和 N-H 键，多 C-C 和 C-N 键形成级联环化与 1,2-二酮，随后进行侧链烷基化，从而构建了功能化的五取代吡咯及其手性类似物。该多米诺反应的范围已成功扩展到通过不寻常的侧链胺化、消除和环缩合来合成高度芳基取代的吡咯、带有 C2-烯基侧链的五取代吡咯、螺-2-吡咯烷酮及其手性类似物。新的多米诺反应操作简单、稳健、具有底物特异性、选择性和高产率。
