Relay rhodium(I)/Brønsted acid catalysis for tandem arylation−cyclization reaction was developed. Chemodivergent syntheses of benzo-2H-pyrans and benzofurans from propargyl alcohols and ortho-hydroxylated arylboronic acids were achieved under this relay catalysis system. An ortho-hydroxy effect on changing the chemoselectivity and reactivity was observed.
Bifunctionalized Allenes, Part IX: An Efficient Method for Regioselective Synthesis of 4-Heteroatom-Functionalized Allenecarboxylates
作者:Ivaylo K. Ivanov、Ivaylo D. Parushev、Valerij Ch. Christov
DOI:10.1002/hc.21096
日期:2013.7
An efficient method for regioselective synthesis of 4-heteroatom-functionalized allenecarboxylates by an atom economical [2,3]-sigmatropic rearrangement of the mediated 2-heteroatom-functionalized alk-3-ynecarboxylates is described. Alkyl 4-(dimethoxyphosphoryl), (diphenylphosphinoyl), (benzenesulfinyl), or (methanesulfonyl)-alka-2,3-dienoates can be readily prepared via reactions of alkyl 2-hydroxy-alk-3-ynoates