Iron-Catalyzed Oxidative Cross-Coupling of Phenols and Alkenes
作者:Umesh A. Kshirsagar、Clil Regev、Regev Parnes、Doron Pappo
DOI:10.1021/ol401532a
日期:2013.6.21
A novel bioinspired iron-catalyzedoxidativecross-coupling reaction betweenphenols and conjugated alkenes was developed. This method enables the direct coupling of phenols with styrene, α-alkyl- and α-arylstyrenes, β-alkyl styrenes, and stilbenes, thereby providing a new strategy for the preparation of the pharmacologically important 2,3-dihydrobenzofuran motif. In addition, this study revealed that
The first highly enantioselective [3 + 2] formal cycloaddition of 1-styrylnaphthols (or phenol) with quinones catalyzed by a chiralphosphoricacid has been reported. A class of trans-2,3-diarylbenzofurans were prepared efficiently (up to 99% yield, >20:1 dr, 99% ee). This organocatalytic procedure allows lowering of the catalyst loading to 0.5 mol % without considerable loss in reactivity and enantioselectivity
A new method for synthesis of benzofurans and naphthofurans from 2-hydroxystilbene derivatives via an intermolecular cyclization is reported in this study with up to 94% isolated yield.
Asymmetric synthesis of triarylsubstituted chromanes with multiple adjacent stereogenic centers is described here. [4+2] formal oxa ‐Diels‐Alder cycloaddition of 1‐styrylnaphthols and in‐situ ‐generated o‐quinone metheides could proceed smoothly in the presence of H 8 ‐BINOL‐type chiral imidodiphosphoric acid as catalyst. This method provides an efficient strategy to construct chiral chromane frameworks
An efficient method to construct enantioenriched spiro[benzofuro-cyclopenta[1,2-b]indole–indoline] scaffolds via consecutive cyclization is described here. The new scaffolds possess five successive chiral stereogenic centers and two spiroheterocycles. A range of highly enantioenriched scaffolds has been obtained with up to 93% yield, 99% ee and >19 : 1 d.r. catalyzed by Brønsted acid catalysts.
本文描述了一种通过连续环化来构建对映体富集的螺[苯并呋喃-环戊五[1,2 - b ]吲哚-吲哚啉]支架的有效方法。新的支架具有五个连续的手性立体发生中心和两个螺杂环。已经获得了一系列高度对映体富集的支架,其通过布朗斯台德酸催化剂催化的产率高达93%,ee为99%,dr> 19:1 dr。