Pd-catalyzed oxidative homocoupling of arylboronic acids in WEPA: A sustainable access to symmetrical biaryls under added base and ligand-free ambient conditions
report, a quick and eco-friendly protocol for the synthesis of biaryls by an oxidative (aerobic) homocoupling of arylboronicacids (ABAs) using Pd(OAc)2 in water extract of pomogranate ash (WEPA) as an efficient agro-waste(bio)-derived aqueous (basic) media. The reactions were executed at ambient aerobicconditions in the absence of external base and ligand to result symmetrical biaryls in excellent
Copper terephthalate MOF is utilised as an environmentally benign, efficient and reusable heterogeneous catalyst to effect the aerobic homocoupling of arylboronic acids yielding the corresponding symmetrical biphenyls under mild reaction conditions. This method tolerates various substituents present in arylboronic acids such as halogens, cyano and nitro groups. The catalytic performance has been compared with that of other copper based MOFs namely MOF-101, [Cu(pdc)2]NH2Me2, [Cu2(ndc)2ted]n and [Cu(H2L)]n as well as with other copper salt catalysts. Sheldon test confirmed the heterogeneity of the catalyst, which can be reused under optimized conditions with only a minor loss in its activity. A mechanism for the homocoupling reaction is also proposed. The simplicity of catalyst preparation, its stability, substrate selectivity, easy recovery and regeneration designate possible utilization of this catalytic system in a multitude of catalytic reactions and industrial processes.
The transition-metal-catalyst-free oxidative homocoupling of organomanganese reagents prepared by the insertion of magnesium into organic halides in the presence of MnCl<sub>2</sub>·2LiCl
作者:Zhihua Peng、Na Li、Xinyang Sun、Fang Wang、Lanjian Xu、Cuiyu Jiang、Linhua Song、Zi-Feng Yan
DOI:10.1039/c4ob01235f
日期:——
An oxidative homocoupling of organomanganese reagents was performed in one pot without an additional transition-metal catalyst.
有机锰试剂的氧化自偶联在一个锅中进行,无需额外的过渡金属催化剂。
A general gold-catalyzed direct oxidative coupling of non-activated arenes
作者:Anirban Kar、Naveenkumar Mangu、Hanns Martin Kaiser、Matthias Beller、Man Kin Tse
DOI:10.1039/b714928j
日期:——
A gold-catalyzed mild and general oxidative homo-coupling of arenes using PhI(OAc)2 as the oxidant is described (13 examples, 31-81% yield).
[EN] STEREOSELECTIVE PREPARATION OF SUBSTITUTED PIPERIDINES
申请人:PFIZER INC.
公开号:WO1992017449A1
公开(公告)日:1992-10-15
(EN) Novel processes are disclosed for the stereoselective preparation of substituted piperidine derivatives of formulae (IV) and (I) wherein R1 and R2 are defined as below.(FR) Nouveaux procédés de préparation stéréosélective de dérivés de pipéridine substituée répondant aux formules (IV) et (I), dans lesquelles R1 et R2 ont les mêmes notations que ci-dessous.