Catalytic carbonyl hydrosilylations via a titanocene borohydride–PMHS reagent system
作者:Godfred D. Fianu、Kyle C. Schipper、Robert A. Flowers II
DOI:10.1039/c7cy01088e
日期:——
Reduction of a wide range of aldehydes and ketones with catalytic amounts of titanocene borohydride in concert with a stoichiometric poly(methylhydrosiloxane) (PMHS) reductant is reported. Preliminary mechanistic studies demonstrate that the reaction is mediated by a reactive titanocene(III) complex, whose oxidation state remains constant throughout the reaction.
Highly Chemoselective Catalytic Hydrogenation of Unsaturated Ketones and Aldehydes to Unsaturated Alcohols Using Phosphine-Stabilized Copper(I) Hydride Complexes
作者:Jian-Xin Chen、John F. Daeuble、Donna M. Brestensky、Jeffrey M. Stryker
DOI:10.1016/s0040-4020(99)01098-4
日期:2000.4
phenyldimethylphosphine-stabilized copper(I) hydride complex provides for the highly chemoselective hydrogenation of unsaturated ketones and aldehydes to unsaturated alcohols, including the regioselective 1,2-reduction of α,β-unsaturated ketones and aldehydes to allylic alcohols. The active catalyst can be derived in situ by phosphine exchange using commercial [(Ph3P)CuH]6 or from the reaction of copper(I) chloride
Cerium-free Luche reduction directed by rehydrated alumina
作者:Ebenezer Jones-Mensah、Leslie A. Nickerson、Jackson L. Deobald、Hailey J. Knox、Alyssa B. Ertel、Jakob Magolan
DOI:10.1016/j.tet.2016.03.017
日期:2016.6
A 1,2-regioselective reduction of α,β-unsaturatedketones to their corresponding allylicalcohols is accomplished with NaBH4 in the presence of acidic activated alumina rehydrated to the Brockmann II grade by adding 3 % w/w water. The substrate scope includes eight ketones reduced in high regio- and diastereoselectivity to their corresponding allylicalcohols. This is the first example of the strategy
Tributyltin chloride-sodium cyanoborohydride mediated tandem radical cyclisation-reductive demethoxylation sequence
作者:A Srikrishna、R Viswajanani、C.V Yelamaggad
DOI:10.1016/s0040-4020(97)00658-3
日期:1997.7
the bromoketals 3, 7a-g and 11 with tri-n-butyltin chloride and sodium cyanoborohydride in the presence of a catalytic amount of AIBN furnished the ethers 5, 8a-g and 13 via a tandemsequence comprising of a radicalcyclisation reaction and tri-n-butylhalostannane and sodium cyanoborohydride mediated reductive demethoxylation of the resulting cyclic ketals.
The regio- and stereoselectivity in the solvomercuriation and intramolecular alkoxymercuriation of several cyclic olefinic alcohols were examined. The regioselectivity is controlled mainly by electronic factors, while the stereoselectivity is controlled by steric factors as well as electronic ones. The optimised structure of the mercurinium ion intermediate suggests that the attractive interaction between the hydroxy group in the molecule and the mercurinium ion moiety affects the selectivity.