A Mechanism Switch in Enyne Metathesis Reactions Involving Rearrangement: Influence of Heteroatoms in the Propargylic Position
摘要:
Novel findings concerning the mechanism of enyne metathesis reactions involving rearrangement are presented. It has been demonstrated that the presence of either oxygen or nitrogen at the propargylic position leads to opposite regioselectivities in the presence of a cross-metathesis partner. The application of these reactions to domino processes is also described.
Radical Borylation/Cyclization Cascade of 1,6-Enynes for the Synthesis of Boron-Handled Hetero- and Carbocycles
作者:Shi-Chao Ren、Feng-Lian Zhang、Jing Qi、Yun-Shuai Huang、Ai-Qing Xu、Hong-Yi Yan、Yi-Feng Wang
DOI:10.1021/jacs.7b01889
日期:2017.5.3
construct boron-handled cyclic molecules was developed based on a radical borylation/cyclization cascade of 1,6-enynes. The process was initiated by the chemo- and regio-controlled addition of an N-heterocyclic carbene-boryl radical to an alkene or alkyne, followed by ring closure to afford boron-substituted cyclic skeletons. Further molecular transformations of the cyclic products to synthetically
Cobalt Nanoparticles on Charcoal: A Versatile Catalyst in the Pauson−Khand Reaction, Hydrogenation, and the Reductive Pauson−Khand Reaction
作者:Seung Uk Son、Kang Hyun Park、Young Keun Chung
DOI:10.1021/ol0268889
日期:2002.10.1
[GRAPHICS]Dispersions of nanometer-sized cobalt particles with very high stability were prepared in charcoal and analyzed by electron microscopy and X-ray analysis. The resulting cobalt nanoparticles on charcoal (CNC) were successfully used as a catalyst for the carbonylative cycloaddition of alkyne, alkene, and carbon monoxide (Pauson-Khand reaction), hydrogenation, and the reductive Pauson-Khand reaction.
Domino metathesis of alkynyl substituted cycloolefins
作者:Anke Rückert、Dirk Eisele、Siegfried Blechert
DOI:10.1016/s0040-4039(01)01003-6
日期:2001.7
Cycloolefins with N- and O-propargyl side chains were converted in good yields to disubstituted dihydropyrroles and dihydrofurans using Grubbs' catalyst in a sequence of enyne metathesis, RCM-ROM and CM. Olefins employed in the final CM step were ethylene and various monosubstituted alkenes. (C) 2001 Elsevier Science Ltd. All rights reserved.