The expanded-ring N-heterocyclic carbenes 6Dipp and 7Dipp (6Dipp = 1,3-bis(2,6-diisopropylphenyl)-3,4,5,6-tetrahydropyrimidin-2-ylidene and 7Dipp = 1,3-bis(2,6-diisopropylphenyl)-4,5,6,7-tetrahydro-1,3-diazepin-2-ylidene) support isolable neutral copper hydride dimers. [(6Dipp)CuH](2) reacts with 1-hexene to give (6Dipp)copper(I) hexyl by 1,2-insertion and with benzyl isonitrile to afford an C-1-formimidoyl by 1,1-insertio
Palladium/NHC-catalyzed oxidative esterification of aldehydes with phenols
摘要:
A palladium-catalyzed oxidative esterification of aldehydes with phenols is described, using air as the clean oxidant. This reaction tolerates many functional groups, providing esters with yields ranging from moderate to excellent. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of Isocoumarins through Three-Component Couplings of Arynes, Terminal Alkynes, and Carbon Dioxide Catalyzed by an NHC-Copper Complex
作者:Woo-Jin Yoo、Thanh V. Q. Nguyen、Shū Kobayashi
DOI:10.1002/anie.201404692
日期:2014.9.15
A copper‐catalyzed multicomponent coupling reaction between in situ generated ortho‐arynes, terminal alkynes, and carbondioxide was developed to access isocoumarins in moderate to good yields. The key to this CO2‐incorporating reaction was the use of a versatile N‐heterocyclic carbene/copper complex that was able to catalyze multiple transformations within the three‐component reaction.
Cyclododecyne (5) as a prototype unstrained alkyne was coordinated to either the neutral [AuCl] fragment or to two different cationic [Au(NHC)]+ entities (NHC=N‐heterocyclic carbene), and the resulting complexes 6, 8, and 10 were characterized by X‐ray crystallography and NMR spectroscopy. Since the structure of cyclododecyne in the solid state could also be obtained after in situ crystallization,
Dial-a-base mechanochemical synthesis of N-heterocyclic carbene copper complexes
作者:Dawid J. Babula、Rex S. C. Charman、Josie A. Hobson、Mary F. Mahon、David J. Liptrot
DOI:10.1039/d4dt00334a
日期:——
Liquid assisted ball milling of [NHC]HBr (NHC = N-heterocycliccarbene) salts with copper(I) chloride, and a range of alkali metal complexes was shown to efficiently produce (NHC)CuX (NHC = normal or RE-NHC, X = halide, alkoxide, amide, alkyl, aryl; RE-NHC = ring-expanded NHC).
[NHC]HBr (NHC = N-杂环卡宾) 盐与氯化铜 ( I ) 和一系列碱金属络合物的液体辅助球磨可有效生产 (NHC)CuX(NHC = 正常或 RE-NHC, X = 卤化物、醇盐、酰胺、烷基、芳基;RE-NHC = 扩环 NHC)。