Copper-Catalyzed Propargylic Reduction with Diisobutylaluminum Hydride
作者:Yuna Kim、Hanseul Lee、Sunga Park、Yunmi Lee
DOI:10.1021/acs.orglett.8b02413
日期:2018.9.7
A mild and efficient method for the synthesis of allenes through selective copper-catalyzed hydride addition to propargylic chlorides using commercially available diisobutylaluminum hydride has been developed. This transformation, which is promoted by a readily accessible N-heterocyclic carbene–copper complex, provides a wide range of new and versatile functionalized allenes in good to excellent yields
Rhodium-catalyzed addition of sulfonyl hydrazides to allenes: regioselective synthesis of branched allylic sulfones
作者:Vahid Khakyzadeh、Yu-Hsuan Wang、Bernhard Breit
DOI:10.1039/c7cc02375h
日期:——
A rhodium-catalyzed regioselective addition of sulfonyl hydrazides to allenes is reported. With Rh(I)/DPEphos/benzoic acid as the catalyst system, branched allylic sulfones can be obtained, in good to excellent yields and regioselectivities.
Counterions in control: The rhodium(I)‐catalyzed coupling of one molecule of aldehyde and two molecules of allene gave β,γ‐dialkylidene ketones (see scheme). Either of two constitutional isomers was selectively obtained depending on the counterion of the rhodium(I) complex.
Rh/Lewis Acid Catalyzed Regio-, Diastereo- and Enantioselective Addition of 2-Acyl Imidazoles with Allenes
作者:Pranjal P. Bora、Gui-Jun Sun、Wei-Feng Zheng、Qiang Kang
DOI:10.1002/cjoc.201700596
日期:2018.1
A highly regio‐, diastereo‐ and enantioselective addition of 2‐acylimidazoles or 2‐acyl pyridines with allenes promoted by Rh/Lewis acid synergistically catalytic system is described. This atom economic approach leads to the formation of the branched allylic alkylated products including acyclic quaternary all‐carbon stereogenic centres in good yields with good to excellent diastereo‐ and enantioselectivities
Enantioselective [2 + 2 + 2] Cycloaddition Reaction of Isocyanates and Allenes Catalyzed by Nickel
作者:Tomoya Miura、Masao Morimoto、Masahiro Murakami
DOI:10.1021/ja105541r
日期:2010.11.17
The enantioselective intermolecular [2 + 2 + 2] cycloaddition reaction of two molecules of isocyanate and one molecule of allene is catalyzed by a nickel(0)/(S,S)-i-Pr-FOXAP complex, providing an efficient access to enantiomerically enriched dihydropyrimidine-2,4-diones.