secondary benzylic alcohols via tandem Ni-catalyzed cross-coupling reactions of aromatic 2-pyridyl esters with alkyl zinc reagents and carbonyl group reduction by Ni–H species is achieved. Preliminary mechanistic studies reveal that the Ni–H species is generated in situ via β-hydride elimination of the Negishi reagents. The reaction is catalyzed by bench-stable nickel salts under mild conditions with
Tandem Catalysis: Alcohol Oxidation and CC Bond Formation via CH Bond Activation
作者:Marc-Olivier Simon、Gaël Ung、Sylvain Darses
DOI:10.1002/adsc.201000884
日期:2011.5.9
A tandem process involving oxidation of a benzylicalcohol functionality followed by hydroarylation is described. These two atom‐economic sequences are very convenient to access functionalized aromatic ketones, using simple ruthenium trichloride as catalyst precursor. Moreover they appear to be highly compatible, tolerant, and selective toward various functional groups, and the ease of the protocol
Rhodium-Catalyzed Alkenylation of Toluene Using 1-Pentene: Regioselectivity To Generate Precursors for Bicyclic Compounds
作者:Nichole S. Liebov、Weihao Zhu、Junqi Chen、Michael S. Webster-Gardiner、William L. Schinski、T. Brent Gunnoe
DOI:10.1021/acs.organomet.9b00535
日期:2019.10.14
compounds. The olefin concentration, copper(II) oxidant identity and concentration, reaction temperature, and rhodium concentration for the alkenylation of toluene with 1-pentene have been optimized using [Rh(η2-C2H4)2(μ-OAc)]2 as the catalyst precursor. The rhodium-based catalysis achieves up to 12(1):1 anti-Markovnikovselectivity for 1-tolyl-1-pentenes over 2-tolyl-2-pentenes and is selective for alkenylation
Nickel-Catalyzed Alkylation of Aldehydes with Trialkylboranes
作者:Koji Hirano、Hideki Yorimitsu、Koichiro Oshima
DOI:10.1021/ol051917b
日期:2005.10.1
[reaction: see text] Nickel-catalyzed alkylation of aldehydes with trialkylboranes proceeds smoothly in the presence of a catalytic amount of 5-allyl-1,2,3,4,5-pentamethyl-1,3-cyclopentadiene or an excess of cesium carbonate to afford the corresponding secondary alcohols.
An NMR study of a 1 : 1 mixture of a chiral lithium amide (4a) and n-BuLi shows that depending on the solvent employed (Et2O or THF) a mixed aggregate can form in proportions that are directly related to the ees measured during the enantioselective alkylation of o-tolualdehyde by these same species.