The first example of the thiyl radical promoted ligand-free iron-catalyzed oxidative cleavage of alkenes using molecular oxygen (1 atm) has been developed. The reaction proceeds under mild reaction conditions with high efficiency and high chemo- and regioselectivity. It features a broad substrate scope and excellent functional group compatibility, enabling facile access to valuable molecules for application
methylenation of acyl fluorides and acyl chlorides with substituted with aryl, alkenyl, and alkyl groups trimethylaluminum afforded an array of 2-substituted propene derivatives. The addition of a catalytic amount of DPPM increased an efficiency of the reactions. Trimethylaluminum as the methylenation reagent not only eliminates the presynthesis of methylene transfer reagent, but provides an efficient method for
Pd-Catalyzed Regioselective 1,2-Difunctionalization of Vinylarenes with Alkenyl Triflates and Aryl Boronic Acids at Ambient Temperature
作者:Zhijie Kuang、Kai Yang、Qiuling Song
DOI:10.1021/acs.orglett.7b01036
日期:2017.5.19
A Pd-catalyzed highly regioselective 1,2-difunctionalization of vinylarenes is disclosed in which multisubstituted olefins are efficiently and conveniently constructed under ambient temperature with good compatibility and a broad substrate scope. Notably, a quarternary carbon center could be readily built up from 1,1-disubstituted styrenes, which are big challenges in the previous methods.
Gold-Catalyzed Oxa-Povarov Reactions for the Synthesis of Highly Substituted Dihydrobenzopyrans from Diaryloxymethylarenes and Olefins
作者:Vinayak Vishnu Pagar、Chang-Chin Tseng、Rai-Shung Liu
DOI:10.1002/chem.201403285
日期:2014.8.11
Oxa‐Povarov reactions involving readily available diaryloxymethylarenes and aryl‐substituted alkenes are reported. Their [4+2] cycloadditions were efficiently catalyzed by IPrAuSbF6 (IPr=1,3‐bis(diisopropylphenyl)imidazol‐2‐ylidene) with high diastereoselectivity. Product analysis revealed that the reactions likely proceed by a stepwise ionic mechanism, because both E‐ and Z‐configured β‐methylstyrene
Herein, we report an unprecedented regiospecific oxidative Mizoroki-Heck type reaction for the synthesis of α-difluoromethyl homoallylic alcohols. The reaction shows broad substrate scopes and high functional group tolerance. Late-stage functionalization of complex biologically active molecules demonstrates the synthetic potential of this transformation. Mechanistic study supports the involvement of