Ligand‐Controlled Diastereoselective Cobalt‐Catalysed Hydroalkynylation of Terminal Alkynes to
<i>E</i>
‐ or
<i>Z</i>
‐1,3‐Enynes
作者:Sebastian M. Weber、Jona Queder、Gerhard Hilt
DOI:10.1002/chem.202001697
日期:2020.9.21
A diastereoselectivehydroalkynylation of terminalalkynes to form the head‐to‐head dimerization products by two different cobalt‐phosphine catalyst system is reported. The use of the bidentate ligand dppp and additional triphenylphosphine led to the selective formation of the (E)‐1,3‐enynes (E:Z>99:1) in good to excellent yields, while the tridentate ligand TriPhos led to the corresponding (Z)‐1,3‐enynes
Hydrido-Cobalt Catalyst as a Selective Tool for the Dimerisation of Arylacetylenes: Scope and Theoretical Studies
作者:Sandrine Ventre、Etienne Derat、Muriel Amatore、Corinne Aubert、Marc Petit
DOI:10.1002/adsc.201300486
日期:2013.9.16
A simple hydrido‐cobaltcomplex efficiently catalyses the highly regio‐ and stereoselective dimerisation of various terminal arylacetylenes under mild conditions. The corresponding (E)‐1,4‐enynes are obtained as sole isomers with good to excellent yields. DFT calculations revealed that the reaction proceeds via a CH activation/hydrocobaltation pathway.
General and Selective Head-to-Head Dimerization of Terminal Alkynes Proceeding via Hydropalladation Pathway
作者:Claire Jahier、Olga V. Zatolochnaya、Nickolay V. Zvyagintsev、Valentine P. Ananikov、Vladimir Gevorgyan
DOI:10.1021/ol3010936
日期:2012.6.1
A general highly regio- and stereoselective palladium-catalyzed head-to-headdimerization reaction of terminal acetylenes is presented. This methodology allows for the efficient synthesis of a variety of 1,4-enynes as single E stereoisomers. Computational studies reveal that this dimerization reaction proceeds via the hydropalladation pathway.
<i>Z</i>-Selective (Cross-)Dimerization of Terminal Alkynes Catalyzed by an Iron Complex
作者:Orestes Rivada-Wheelaghan、Subrata Chakraborty、Linda J. W. Shimon、Yehoshoa Ben-David、David Milstein
DOI:10.1002/anie.201601382
日期:2016.6.6
Efficient iron‐catalyzed homocoupling of terminal alkynes and cross‐dimerization of aryl acetylenes with trimethylsilylacetylene is reported. The complex [Fe(H)(BH4)(iPr‐PNP)] (1) catalyzed the (cross‐)dimerization of alkynes at room temperature, with no need for a base or other additives, to give the corresponding dimerized products with Z selectivity in excellent yields (79–99 %).