Gold(I)-catalyzed intermolecular hydroarylation of alkenes with indoles under thermal and microwave-assisted conditions.
An efficient method for intermolecular hydroarylation of aryl and aliphatic alkenes with indoles using a combination of [(PR(3))AuCl]/AgOTf as catalyst under thermal and microwave-assisted conditions has been developed. The gold(I)-catalyzed reactions of indoles with aryl alkenes were achieved in toluene at 85 degrees C over a reaction time of 1-3 h with 2 mol% of [(PR(3))AuCl]/AgOTf as catalyst. This method works for a variety of styrenes bearing electron-deficient, electron-rich, and sterically bulky substituents to give the corresponding products in good to high yields (60-95%). Under microwave irradiation, coupling of unactivated aliphatic alkenes with indoles gave the corresponding adducts in up to 90% yield. Selective hydroarylation of terminal C=C bond of conjugated dienes with indoles gave good product yields (62-81%). On the basis of deuterium-labeling experiments, a reaction mechanism involving nucleophilic attack of Au(I)-coordinated alkenes by indoles is proposed.
Wang
Ming-Zhong
MZ
Department of Chemistry and Open Laboratory of Chemical Biology of the Institute of Molecular Technology for Drug Discovery and Synthesis, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
Wong
Man-Kin
MK
Che
Chi-Ming
CM
D000466:Alkadienes / Q000138:chemical synthesis / Q000737:chemistry / Q000528:radiation effects; D000475:Alkenes / Q000737:chemistry* / Q000528:radiation effects; D002384:Catalysis; D003516:Cycloparaffins / Q000138:chemical synthesis / Q000737:chemistry / Q000528:radiation effects; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry* / Q000528:radiation effects; D008872:Microwaves; D015394:Molecular Structure; D050607:Organogold Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature
D000466:Alkadienes; D000475:Alkenes; D003516:Cycloparaffins; D007211:Indoles; D050607:Organogold Compounds