Construction of 2-Substituted-3-Functionalized Benzofurans via Intramolecular Heck Coupling: Application to Enantioselective Total Synthesis of Daphnodorin B
A novel approach was developed for the synthesis of 2-substituted-3-functionalized benzofurans, using an intramolecular Heckreaction which was further applied in the first enantioselectivetotalsynthesis of Daphnodorin B.
Controllable Rh(III)-Catalyzed Annulation between Salicylaldehydes and Diazo Compounds: Divergent Synthesis of Chromones and Benzofurans
作者:Peng Sun、Shang Gao、Chi Yang、Songjin Guo、Aijun Lin、Hequan Yao
DOI:10.1021/acs.orglett.6b03355
日期:2016.12.16
A Rh(III)-catalyzed annulation between salicylaldehydes and diazocompounds with controllable chemoselectivity is described. AgNTf2 favored benzofurans via a tandem C–H activation/decarbonylation/annulation process, while AcOH led to chromones through a C–H activation/annulation pathway. The reaction exhibited good functional group tolerance and scalability. Moreover, only a single regioisomer of benzofuran
Tandem Ullmann–Goldberg Cross-Coupling/Cyclopalladation-Reductive Elimination Reactions and Related Sequences Leading to Polyfunctionalized Benzofurans, Indoles, and Phthalanes
作者:Faiyaz Khan、Mehvish Fatima、Moheb Shirzaei、Yen Vo、Madushani Amarasiri、Martin G. Banwell、Chenxi Ma、Jas S. Ward、Michael G. Gardiner
DOI:10.1021/acs.orglett.9b02235
日期:2019.8.16
Cu[I]- and Pd[0]-based catalysts, compounds such as 1 and 7 engage in tandem Ullmann–Goldberg cross-coupling and cyclopalladation-reductive elimination reactions to givebenzofurans such as 8. Related reactions involving hetero-Michael additions of o-halogenated phenols or anilines to propiolates and the Pd[0]-catalyzed cyclization of the resulting conjugates provide, in a one-pot process, alternately
3-Disubstituted benzofurans were synthesized from acrolein dimer and 1,3-dicarbonyl compounds by using N-bromosuccinimide as an oxidizing agent. The method was used to synthesize two commercial drug molecules, benzbromarone and amiodarone. The proposed mechanism of the reaction involves a N-bromosuccinimide (NBS)-assisted autotandem catalysis with Lewis acid catalyst. To proof the proposed mechanism
<i>De novo</i> synthesis of benzofurans <i>via</i> trifluoroacetic acid catalyzed cyclization/oxidative aromatization cascade reaction of 2-hydroxy-1,4-diones
作者:Qiang Sha、Haixuan Liu
DOI:10.1039/c9ob01422e
日期:——
for the de novo synthesis of benzofurans from 2-hydroxy-1,4-diones is described. Using trifluoroacetic acid (TFA) as the catalyst and N-bromobutanimide (NBS) as the oxidant, 2-hydroxy-1,4-diones underwent a cyclization/oxidative aromatization cascade reaction to afford a variety of benzofuran derivatives in moderate to good yields. This is a practically useful method for the synthesis of benzofuran derivatives