Jimoh Tijani

Palladium(II)-catalyzed regioselective carbonylative coupling of aniline derivatives with terminal aryl acetylenes to give acrylamides under syngas conditions

Abstract The carbonylative coupling of aniline derivatives (1a–h) with terminal aryl acetylenes (2a, b) catalyzed by Pd(OAc)2 and 1,4-bis(diphenylphosphino)butane (dppb) under syngas conditions affords acrylamide derivatives 3 or 3′ in excellent yields and selectivities.

Total regioselective control of the carbonylative coupling of 1-heptyne with aniline and N-methyl aniline catalyzed by palladium(II) and phosphine ligand

Abstract The carbonylative coupling of 1-heptyne ( 1a ) with aniline ( 2a ) has been successfully achieved in the presence of Pd(OAc) 2 and a suitable bidentate phosphine ligand and solvent. The gem -α,β-unsaturated amide ( 3aa ) was formed as a predominant product in the presence of the catalytic system Pd(OAc) 2 /1,3-bis(diphenylphosphino)propane (dppp)/ p -toluenesulfonic acid ( p -TsOH)/CO in THF as a solvent. While the use Pd(OAc) 2 and 1,4-bis(diphenylphosphino)butane (dppb), under syngas (CO/H 2 ) conditions and in CH 2 Cl 2 as a solvent, affords the trans -α,β-unsaturated amide ( 4aa ) as the major product. A minor cyclic product ( 5aa ) was formed via the double carbonylation reaction. The regioselective carbonylative coupling reaction was also successfully applied to N -methyl aniline ( 2b ) with 1-heptyne ( 1a ) producing excellent yields of tertiary unsaturated amides.

Regioselective control of the thiocarbonylation of terminal acetylenes with arylthiols catalyzed by Pd(II) and diphosphine ligands

Abstract Control of the regioselective thiocarbonylation of terminal acetylenes 1a – e with arylthiols 2a , b was successfully achieved by using Pd(OAc) 2 and 1,4-bis(diphenylphosphino)butane (dppb), or 1,3-bis(diphenylphosphino)propane (dppp), as catalysts. The formation of the thioesters 3 or 4 depends mainly on the type of ligand (dppp or dppb) and the solvent (THF or CH 2 Cl 2 ) under CO/H + or syngas mixture.

Pd(II)—dppb and syngas catalyze regioselective hydroesterification of terminal alkynes under neutral conditions

Palladium(II) regioselectively catalyzes the hydroesterification of terminal alkynes under syngas forming α,β-unsaturated esters 3 and 4 in excellent chemical yields under neutral conditions. The high selectivity for the linear ester 4 was obtained with a catalytic system that includes Pd(II), 1,4-bis(diphenylphosphino)butane (dppb) and CO/H2 in CH2Cl2 as solvent. The control of the regioselectivity depends strongly upon the type of ligand, the solvent and the use of the syngas mixture.