An expedient synthesis of enantioenriched substituted (2-benzofuryl)arylcarbinols via tandem Rap–Stoermer and asymmetric transfer hydrogenation reactions
An expedientsynthesis of enantioenriched substituted (benzofuran-yl)-aryl and heteroaryl carbinols, is described. A key feature of this protocol is synthesis of functionally varied benzofuran scaffolds via a Rap–Stoermer reaction/catalytic asymmetric transfer hydrogenation (ATH) using substituted salicylaldehyde and α-haloaryl, heteroaryl ketones.
Metal-Free Intermolecular Coupling of Arenes with Secondary Amides: Chemoselective Synthesis of Aromatic Ketimines and Ketones, and <i>N</i>-Deacylation of Secondary Amides
作者:Pei-Qiang Huang、Ying-Hong Huang、Kai-Jiong Xiao
DOI:10.1021/acs.joc.6b01647
日期:2016.10.7
The direct transformation of common secondary amides into aromatic ketimines and aromatic ketones with C–C bond formation is described. The reaction can also be used for N-deacylation of secondary amides to release amines. This method consists of in situ amide activation with triflic anhydride and intermolecular capture of the resulting highly electrophilic nitrilium intermediate with an arene. The
Syntheses of 2-Aroyl Benzofurans through Cascade Annulation on Arynes
作者:Pashikanti Gouthami、Lahu N. Chavan、Rambabu Chegondi、Srivari Chandrasekhar
DOI:10.1021/acs.joc.8b00360
日期:2018.3.16
The highlyefficient and expedient route for the syntheses of 2-aroyl benzofurans has been developed via the cascade [2+2] followed by a [4+1] annulation on arynes. The overall transformation proceeded through the formation of ortho-quinone methide by the insertion of transient aryne into N,N-dimethylformamide and subsequent trapping with sulfurylide. Moreover, this transformation has a broad range
Palladium-catalyzed paraformaldehyde insertion: a three-component synthesis of benzofurans
作者:Xiufang Cheng、Yi Peng、Jun Wu、Guo-Jun Deng
DOI:10.1039/c6ob00198j
日期:——
An efficient procedure for 2-aroylbenzofuran preparationfrom 2-bromophenols, phenacyl bromides and paraformaldehyde is described. The cheap and stable paraformaldehyde served as the carbon source via an in situ formylation reaction.
Formal [4 + 1] cycloaddition of o-quinone methides: facile synthesis of dihydrobenzofurans
作者:Xiantao Lei、Chun-Huan Jiang、Xiaoan Wen、Qing-Long Xu、Hongbin Sun
DOI:10.1039/c4ra17003b
日期:——
An efficient and straightforward method for the rapid synthesis of 2-substituted dihydrobenzofurans has been developed via reaction of sulfur ylides with o-quinonemethides (o-QMs), which were generated under mild conditions. The products could be obtained in excellent yields with various kinds of sulfur ylides.