Aerobic Oxidative Heck/Dehydrogenation Reactions of Cyclohexenones: Efficient Access to<i>meta</i>-Substituted Phenols
作者:Yusuke Izawa、Changwu Zheng、Shannon S. Stahl
DOI:10.1002/anie.201209457
日期:2013.3.25
catalyst, employing a 6,6′‐dimethyl‐2,2′‐bipyridine ligand, promotes both the aerobic oxidative Heck coupling and dehydrogenation reactions of cyclohexenones. These reactions may be combined in a one‐pot sequence to enable the straightforward synthesis of meta‐substituted phenols (see scheme).
Addition reaction of arylboronic acids to aldehydes and α,β-unsaturated carbonyl compounds catalyzed by conventional palladium complexes in the presence of chloroform
作者:Tetsuya Yamamoto、Michiko Iizuka、Hiroto Takenaka、Tetsuo Ohta、Yoshihiko Ito
DOI:10.1016/j.jorganchem.2008.12.032
日期:2009.4
Arylboronic acids react with aldehydes and α,β-unsaturatedcarbonylcompounds in the presence of a base and a catalytic amount of a palladium(0) complex with chloroform, affording the corresponding addition products in good yields, and chiral benzhydrol was obtained with up to 43% e.e. using (S,S)-bppm as a ligand. General palladium complexes have no catalytic activity without chloroform. Because chloroform
The manuscript describes a novel and efficient transition-metal-free approach to substituted phenols from simple and readily available cyclohexenones and cyclohexanones. Dimethyl sulfoxide (DMSO), the simple and common organic reagent, was...
Functionalized Alkenylzinc Reagents Bearing Carbonyl Groups: Preparation by Direct Metal Insertion and Reaction with Electrophiles
作者:Christoph Sämann、Matthias A. Schade、Shigeyuki Yamada、Paul Knochel
DOI:10.1002/anie.201302058
日期:2013.9.2
cyclic and acyclic alkenylzinc reagents bearing functional groups such as aldehyde, keto, and ester groups were readily prepared by either direct zinc insertion in the presence of LiCl or by magnesiuminsertion in the presence of LiCl and ZnCl2. Subsequent functionalization reactions, such as Negishi cross‐couplings, acylations, and allylations, furnished polyfunctional compounds in excellent yields
Preparation of polyfunctional aryl and alkenyl zinc halides from functionalized unsaturated organolithiums and their reactivity in cross-coupling and conjugated addition reactions
作者:Ingo Klement、Mario Rottländer、Charles E. Tucker、Tahir N. Majid、Paul Knochel、Patricia Venegas、Gérard Cahiez
DOI:10.1016/0040-4020(96)00246-3
日期:1996.5
organolithiums which are stable for a short time at these low temperatures and can be transmetalated to organozinc derivatives by the addition of zinc bromide. The resulting unsaturated organozinc halides can then be warmed up and are perfectly stable at 25 °C. They react directly with tosyl cyanide. In the presence of CuCN·2LiCl, they add in a Michael-fashion to alkylidenemalonates. In the presence