Well-defined [Rh(NHC)(OH)] complexes enabling the conjugate addition of arylboronic acids to α,β-unsaturated ketones
作者:Byron J. Truscott、George C. Fortman、Alexandra M. Z. Slawin、Steven P. Nolan
DOI:10.1039/c1ob06112g
日期:——
The synthesis and catalytic activity of three well-defined monomeric rhodium(I) hydroxide complexes bearing N-heterocyclic carbene (NHC) ligands are reported. [Rh(cod)(ICy)(OH)] promoted the 1,4-addition of arylboronic acids to cyclic enones, with TONs and TOFs of 100,000 and 6,600 h−1, respectively, at 0.001 mol% catalyst loadings. Mechanistic studies permitted the isolation of a phenylrhodium intermediate
报道了三种带有N-杂环卡宾(NHC)配体的定义明确的单体铑铑(I)配合物的合成和催化活性。[Rh(cod)(ICy)(OH)]促进了芳基硼酸向环状烯酮的1,4-加成,在0.001 mol%的催化剂负载量下,TON和TOF分别为100,000和6,600 h -1。机理研究允许分离出苯基铑中间体。
Pd-catalysed conjugate addition of arylboronic acids to α,β-unsaturated ketones under microwave irradiation
Pd-catalysed conjugateaddition of arylboronicacids to α,β-unsaturatedcyclic ketones was studied under controlled microwave irradiation conditions. A variety of catalysts, bases and solvents was explored in order to achieve optimum yields in the shortest possible reaction time. Under optimised conditions (Pd(OAc)2/2,2′-bipyridine and KF in a mixture of toluene, water, and acetic acid and 10 min microwave
Olefin-Oxazolines (OlefOx): Highly Modular, Easily Tunable Ligands for Asymmetric Catalysis
作者:Björn T. Hahn、Friederike Tewes、Roland Fröhlich、Frank Glorius
DOI:10.1002/anie.200905712
日期:2010.2.1
the new highly modular family of olefin–oxazoline ligands (OlefOx; see picture) to be exploited in asymmetriccatalysis. The ease of electronic and steric variation and the successful application in the highly enantioselective rhodium‐catalyzed conjugate addition of arylboronic acids to cylic enones demonstrate the importance of this new ligand class.
Rhodium-catalyzed conjugate addition of arylindium reagents to α,β-unsaturated carbonyl compounds
作者:Rubén Tato、Ricardo Riveiros、José Pérez Sestelo、Luis A. Sarandeses
DOI:10.1016/j.tet.2011.11.075
日期:2012.2
A novel rhodium-catalyzedconjugateaddition of indium reagents to electron deficient olefins is reported. The reaction takes place in THF/MeOH at 110 °C using arylindium dichlorides, a rhodium(I)-binap complex as catalyst, and α,β-unsaturated ketones and lactones in good yields (45–94%). The addition of MeOH is crucial for an efficient transformation and NMR studies seem to indicate that promotes
containing a rigid dihydroanthracenyl skeleton are suitable precursors for both organometallic and organo-based catalysts. A Rh–carbene complex and the triazolium salt efficiently catalyzed the 1,4-additions of C- and heterodonor reagents to α,β-unsaturatedcarbonyl substrates, respectively.