A Phosphine-Catalyzed Preparation of 4-Arylidene-5-imidazolones
摘要:
A simple and efficient method for constructing 4-arylidene-S-imidazolones was developed using a phosphine-catalyzed tandem umpolung addition and intramolecular cyclization of amidine pronucleophiles on arylpropiolates. The reaction offers a robust route to heterocycle analogues of the fluorescent protein chromophores.
Novel Catalyst System for Hydrostannation of Alkynes
作者:Sreya Gupta、Youngshil Do、Jin Hee Lee、Miryeong Lee、Junghoon Han、Young Ho Rhee、Jaiwook Park
DOI:10.1002/chem.201303057
日期:2014.1.27
A catalystsystem was developed for the highly regio‐ and stereoselective hydrostannation of a range of alkynes with tributylstannane under mild conditions. The active catalytic species was generated from a stable diruthenium complex by illuminating household fluorescent light (30 W) at room temperature.
Phosphine-catalyzed cage carbon functionalization of o-carborane: facile synthesis of alkenylcarboranes
作者:Fangrui Zheng、Tsz-Fai Leung、Ka-Wing Chan、Herman H. Y. Sung、Ian D. Williams、Zuowei Xie、Guochen Jia
DOI:10.1039/c6cc05283e
日期:——
A phosphine-catalyzed alkenylation reaction of o-carborane with electron-deficient alkynes at the C-H vertex of o-carborane cage has been developed, which led to the preparation of a series of 1-alkenyl-o-carboranes in...
Synthesis of α,β-Alkynyl Esters and Unsymmetrical Maleate Esters Catalyzed by Pd/C; An Efficient Phosphine-Free Catalytic System for Oxidative Alkoxycarbonylation of Terminal Alkynes
作者:Bhalchandra Bhanage、Sandip Gadge
DOI:10.1055/s-0032-1316896
日期:——
Pd/C-catalyzed oxidative alkoxycarbonylation of terminal alkynes using alcohols in the presence of tetrabutylammonium iodide under CO/O-2 (5:1 atm) has been investigated. The desired alpha,beta-alkynyl esters and unsymmetrical maleate esters are formed in good to excellent yields under different reaction conditions. The present protocol eliminates the use of phosphine ligands and has straightforward catalyst recovery. The catalyst was recycled up to six times without significant loss of catalytic activity.