Weak Coordination Promoted Regioselective Oxidative Coupling Reaction for 2,2′-Difunctional Biaryl Synthesis in Hexafluoro-2-propanol
作者:Chao Zhang、Yu Rao
DOI:10.1021/acs.orglett.5b02115
日期:2015.9.18
An unprecedented weak coordination promoted dehydrogenative cross-coupling reaction has been developed by palladium catalysis, which provides a convenient access to a wide range of 2,2′-difunctional biaryls from easily accessible substrates. Both HFIP solvent and oxidants serve as the critical factors in this new reaction. A plausible mechanism involving Pd(II)/Pd(IV) is proposed. The reaction demonstrates
Palladium-Catalyzed Decarboxylative Acylation of<i>O</i>-Phenyl Carbamates with α-Oxocarboxylic Acids at Room Temperature
作者:Satyasheel Sharma、Aejin Kim、Eonjeong Park、Jihye Park、Minyoung Kim、Jong Hwan Kwak、Sang Hwi Lee、Young Hoon Jung、In Su Kim
DOI:10.1002/adsc.201200993
日期:2013.3.11
A palladium‐catalyzed oxidative acylation of O‐phenyl carbamates with α‐oxocarboxylic acids via selective aromatic CH bond activation is described. This protocol represents the first ortho‐acylation of phenol derivatives, and a catalytic amount of triflic acid additive is crucial for this transformation.
Room-temperature Pd-catalyzed C–H chlorination by weak coordination: one-pot synthesis of 2-chlorophenols with excellent regioselectivity
作者:Xiuyun Sun、Yonghui Sun、Chao Zhang、Yu Rao
DOI:10.1039/c3cc47431c
日期:——
A room-temperature Pd(II)-catalyzed regioselective chlorination reaction has been developed for a facile one-pot synthesis of a broad range of 2-chlorophenols. The reaction demonstrates an excellent regioselectivity and reactivity for CâH chlorination. This reaction represents one of the rare examples of mild CâH functionalization at ambient temperature.
A General Approach towards Catechol and Pyrogallol through Ruthenium‐ and Palladium‐Catalyzed CH Hydroxylation by Weak Coordination
作者:Xinglin Yang、Yonghui Sun、Zhang Chen、Yu Rao
DOI:10.1002/adsc.201300999
日期:2014.5.5
An efficient ruthenium(II)‐ and palladium(II)‐catalyzed CH hydroxylation of aryl carbamates has been developed for the facile synthesis of catechols and pyrogallols. The reaction demonstrates excellent reactivity, regio‐ and chemoselectivity, good functional group compatibility and high yields. The practicality of this method has been proved by a gram‐scale synthesis.
RhIII ] complex, bearing an acidic secondary amide moiety on the Cpring, is able to catalyze the ortho-bromination of O-phenyl carbamates with N-bromosuccinimide (NBS) at room temperature. The presence of the acidic secondary amide moiety on the CpA ligand accelerates the bromination by the hydrogen bond between the acidic NH group of the CpA ligand and the carbonyl group of NBS.