24071-99-6Relevant articles and documents
Remote ester group leads to efficient kinetic resolution of racemic aliphatic alcohols via asymmetric hydrogenation
Yang, Xiao-Hui,Wang, Ke,Zhu, Shou-Fei,Xie, Jian-Hua,Zhou, Qi-Lin
supporting information, p. 17426 - 17429 (2015/02/02)
A highly efficient method for kinetic resolution of racemic aliphatic alcohols without conversion of the hydroxyl group has been realized; the method involves hydrogenation mediated by a remote ester group and is catalyzed by a chiral iridium complex. This powerful, environmentally friendly method provides chiral δ-alkyl-δ-hydroxy esters and δ-alkyl-1,5-diols in good yields with high enantioselectivities even at extremely low catalyst loading (0.001 mol %).
Reactions of Grignard reagents with bis- or mono-phosphonium ions in Situ generated from Bu3P and dicarboxylic acid dichlorides or ω-ethoxycarbonyl alkanoyl chlorides as a novel method to obtain diketones and ketoesters
Maeda,Hino,Yamauchi,Ohmori
, p. 1196 - 1199 (2007/10/03)
Reactions of Grignard reagents with bis-phosphonium or mono-phosphonium ions in situ generated from Bu3P and ClCO(CH2)(n)COCl (5) or ClCO(CH2)(n)CO2Et (13) as a tool for preparation of symmetrical diketones or ketoesters were examined. Addition of Bu3P (2.0 eq) to a THF solution of 5 (n=2) at -40°C followed by addition of n-BuMgCl (2.0 eq) gave the corresponding diketone in good yield. When a mixture of Bu3P and the Grignard reagent (2.0 eq each) was added to the dichloride solution at the same temperature, a better result was obtained. The latter method not with PhMgBr but with n-BuMgCl or MeMgBr was shown to be useful for preparation of symmetrical alkanediones and keto alkanoates from various 5 (n=2 - 6) and 13 (n=2 or 3), respectively. For synthesis of α-diketones or α-ketoesters, only PhMgBr entered the reaction, although the yields were not satisfactory. Addition of a mixture of Bu3P (2.0 eq), MeMgBr (1.0 eq) and BuMgCl (1.0 eq) to a THF solution of 5 (n=4) at -40°C afforded a mixture of 2,7-undecanedione and the corresponding two symmetrical diketones, with the yield of the unsymmetrical diketone being 36%.
Highly reactive forms of zinc and reagents thereof
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, (2008/06/13)
A novel zerovalent zinc species and an organozinc reagent are disclosed. The zerovalent zinc species is directly produced by reaction of a reducing agent on a zinc salt, preferably Zn(CN)2. The organozinc reagent results from the reaction of the zerovalent zinc species and an organic compound having one or more stable anionic leaving groups. These organozinc reagents include a wide spectrum of functional groups in the organic radical, and are useful in a variety of reactions schemes.
Organomanganese (II) reagents XXIII: Manganese-catalyzed acylation of organomagnesium compounds by car·ylic acid chlorides
Cahiez, Gerard
, p. 4439 - 4442 (2007/10/02)
In the presence of a catalytic amount of manganese chloride (3% MnCl4Li2), organomagnesium reagents react with car·ylic chlorides, in THF between 0 and 10°C, to give the corresponding ketones in high yields. The scope of the reaction is very large; alkyl, alkenyl and aryl magnesium reagents have been used successfully. The selectivity of the reaction allows to prepare various fonctionalized ketones from car·ylic acid chlorides bearing a functional group (Cl, Br, ester nitrile and even a ketone).
The Direct Formation of Functionalized Alkyl(aryl)zinc Halides by Oxidative Addition of Highly Reactive Zinc with Organic Halides and Their Reactions with Acid Chlorides, α,β-Unsaturated Ketones, and Allylic, Aryl, and Vinyl Halides
Zhu, Lishan,Wehmeyer, Richard M.,Rieke, Reuben D.
, p. 1445 - 1453 (2007/10/02)
Highly reactive zinc, prepared by the lithium naphthalenide reduction of ZnCl2, readily undergoes oxidative addition to alkyl, aryl, and vinyl halides under mild conditions to generate the corresponding organozinc compounds in excellent yields.Significantly, the reaction will tolerate a spectrum of functional groups on the organic halides.Accordingly, this approach can now be used to prepare a wide variety of highly functionalized organozinc compounds.In the presence of Cu(I) salts, the organozinc compounds cross-couple with acid chlorides, conjugatively add to α,β-unsaturated ketones, and regioselectively undergo SN2' substitution reactions with allylic halides.They also cross-couple with aryl or vinyl halides with Pd(0) catalysts.
ORGANOMANGANESE (II) REAGENTS XIX. ACYLATION OF ORGANOMANGANESE CHLORIDES BY CARBOXYLIC ACID CHLORIDES IN THF: A CLEAR IMPROVEMENT IN THE FIELD OF THE PREPARATION OF KETONES FROM ORGANOMANGANESE COMPOUNDS.
Cahiez, Gerard,Laboue, Blandine
, p. 7369 - 7372 (2007/10/02)
Organomanganese chloride reagents react with carboxylic acid chlorides, in THF, to give the corresponding ketones in excellent yields.The reaction is of broad scope, it is very interesting from practical and economical point of view since organomanganese chlorides (in THF) are the most stable and cheap organomanganese reagents.With methyl, aryl, alkenyl and s- or t-alkylmanganese chlorides, the acylation is advantageously performed in the presence of a catalytic amount of copper chloride.This new procedure allows to prepare methyl, aryl and alkenylketones as well as s- or t-alkylketones in good yields.
