Electrophilic Cyclization of 2-Chalcogenealkynylanisoles: Versatile Access to 2-Chalcogen-benzo[b]furans
摘要:
An efficient synthesis of 2-chalcogen-3-substituted-benzo[b]furan compounds has been accomplished via electrophilic cyclization reaction of 2-chalcogenealkynyl anisoles using I-2, ICl, Br-2 and PhSeBr as electrophile sources. The product distributions were strongly dependent on the nature of substituents in the aromatic ring of anisole and on the chalcogen atom directly bonded to the triple bond. The 2-chalcogen-3-iodo-benzo[b]furans obtained smoothly underwent conversion to more complex structures of benzo[b]furan derivatives via palladium- or copper-catalyzed cross-coupling reaction with thiols, diphenyl diselenides, and zincates.
Electrophilic Cyclization of 2-Chalcogenealkynylanisoles: Versatile Access to 2-Chalcogen-benzo[<i>b</i>]furans
作者:Flávia Manarin、Juliano A. Roehrs、Rafaela Mozzaquatro Gay、Ricardo Brandão、Paulo H. Menezes、Cristina W. Nogueira、Gilson Zeni
DOI:10.1021/jo802736e
日期:2009.3.6
An efficient synthesis of 2-chalcogen-3-substituted-benzo[b]furan compounds has been accomplished via electrophilic cyclization reaction of 2-chalcogenealkynyl anisoles using I-2, ICl, Br-2 and PhSeBr as electrophile sources. The product distributions were strongly dependent on the nature of substituents in the aromatic ring of anisole and on the chalcogen atom directly bonded to the triple bond. The 2-chalcogen-3-iodo-benzo[b]furans obtained smoothly underwent conversion to more complex structures of benzo[b]furan derivatives via palladium- or copper-catalyzed cross-coupling reaction with thiols, diphenyl diselenides, and zincates.
Experimental and Computational Studies on the Directing Ability of Chalcogenoethers in Palladium‐Catalyzed Atroposelective C−H Olefination and Allylation
作者:Gang Liao、Tao Zhang、Liang Jin、Bing‐Jie Wang、Cheng‐Kai Xu、Yu Lan、Yu Zhao、Bing‐Feng Shi
DOI:10.1002/anie.202115221
日期:2022.3
of chalcogenoether motifs in Pd-catalyzed atroposelective C−Holefination and allylation are presented. The thioether motif was found to be a superior directing group compared to the corresponding ether (−OR) and selenoether in terms of reactivity and enantiocontrol. The selenoether unit (−SeMe) was used for the first time as a suitable directing group in asymmetric C−H activation.