An Expansible Metalla-cryptand as a Component of a Supramolecular Combinatorial Library Formed from Di(8-hydroxyquinoline) Ligands and Gallium(III) or Zinc(II) Ions
A ruthenium-catalyzed [1,2]-Brook rearrangement involved dominosequence is presented to prepare highly functionalized silyloxy indenes with atomic- and step-economy. This domino reaction is triggered by acylsilane-directed C–H activation, and the aldehyde controlled the subsequent enol cyclization/Brook Rearrangement other than β–H elimination. The protocol tolerates a broad substitution pattern,
Chiral Primary Amine-Catalyzed Divergent Coupling of α-Substituted Acrylaldehydes with α-Diazoesters
作者:Zaikun Xue、Yao Li、Sanzhong Luo
DOI:10.1021/acscatal.0c02405
日期:2020.10.2
We report, herein, aminocatalytic coupling of α-substituted acrylaldehydes with α-diazoesters, leading to chemoselective C–H insertion or cyclopropanation depending on α-substituents of diazoesters. A chiral primary–secondary diamine catalyst derived from l-tert-leucine enabled the efficient promotion of both C–H insertion and cyclopropanation pathways in good yields and high enantioselectivities at
Reactions of Ketene Acetals. III. A New Synthesis of α-Pyrones. II
作者:Alain Bélanger、Paul Brassard
DOI:10.1139/v75-027
日期:1975.1.15
β-unsaturated aldehydes and ketones gives the corresponding 2,2-dialkoxy-3-chloro-3,4-dihydro-1,2-pyrans. Treatment of these compounds with alkoxides in dimethylsulfoxide or dimethylformamide yields α-pyrones directly. Some intermediates and by-products have been identified and the reaction conditions have been studied.
A ruthenium-catalyzed C–H alkylation/cyclization sequence is presented to prepare silyl indenes with atom and step-economy. This domino reaction is triggered by acyl silane-directed C–H activation, and an aldehyde controlled the following enol cyclization/condensation other than β-H elimination. The protocol tolerates a broad substitution pattern, and the further synthetic elaboration of silyl indenes