Palladium-catalyzed cross-coupling of cyclopropylmethyl N-tosylhydrazones with aromatic bromides: an easy access to multisubstituted 1,3-butadienes
摘要:
Direct synthesis of 1,1-disubstitued 1,3-butadienes has been efficiently realized from the cross-coupling of cyclopropylmethyl N-tosylhydrazones with aromatic bromides by means of PdCl2(MeCN)(2) as catalyst. 1,1,4-Trisubstitued 1,3-butadiene derivatives were obtained in up to 70% yields through a one-pot procedure catalyzed by Pd(OAc)(2) in the presence of excessive amount of aromatic bromides. The present methodology provides an easy and efficient route to multisubstituted 1,3-butadienes. (C) 2013 Elsevier Ltd. All rights reserved.
p-Selective (sp2)-C-H functionalization of electron rich arenes have been achieved for acylation and alkylation reaction, respectively, with acyl/alkylselenides by organic photoredox catalysis involving interesting mechanistic pathway.
A palladium-catalyzed dual C–H functionalization of substituted aromatic ketones and ester with maleimides leading to tricyclic heterocyclic molecules with good to excellent yield is reported. In this protocol, weak chelation of the carbonyl groups has been successfully utilized for the selective activation of the ortho-methyl C(sp3)–H bond instead of the ortho-C(sp2)–H bond in the presence of an external