Catalytic Reduction of Phenyl-Conjugated Acetylenic Halides by Nickel(I) Salen: Cyclization versus Coupling
作者:Mohammad S. Mubarak、Theodore B. Jennermann、Michael A. Ischay、Dennis G. Peters
DOI:10.1002/ejoc.200700655
日期:2007.11
to study the catalyticreduction of five phenyl-conjugated haloalkynes by nickel(I) salen electrogenerated at carbon cathodes in dimethylformamide containing tetramethylammonium tetrafluoroborate. Electrocatalytic reduction of 7-bromo- and 7-iodo-1-phenyl-1-heptyne affords the carbocyclic product, benzylidenecyclohexane, in up to 41 % yield, whereas under similar conditions reduction of 5-halo-1-phenyl-1-pentyne
Et<sub>2</sub>Zn-Mediated Rearrangement of Bromohydrins
作者:Lezhen Li、Peijie Cai、Qingxiang Guo、Song Xue
DOI:10.1021/jo800231s
日期:2008.5.1
and highly efficient method for the rearrangement of bromohydrins mediated by Et2Zn to synthesize carbonylcompounds was described. Various β-bromo alcohols were treated with 0.6 equiv of Et2Zn to form a zinc complex in CH2Cl2 at room temperature for 2 h, followed by 1,2-migration to give the corresponding carbonylcompounds. This remarkable and clean rearrangement is general for acyclic and cyclic bromohydrins
Catalytic, oxidant-free, direct olefination of alcohols using Wittig reagents
作者:E. Khaskin、D. Milstein
DOI:10.1039/c5cc02902c
日期:——
Catalytic acceptorless coupling of alcohols with in situ generated phosphonium ylides forms olefins and H2, with significant stereospecificity.
醇与原位生成的磷鎓叶立德的催化无受体偶联形成具有显着立体特异性的烯烃和H 2。
Iron‐Catalyzed Radical Asymmetric Aminoazidation and Diazidation of Styrenes
作者:Daqi Lv、Qiao Sun、Huan Zhou、Liang Ge、Yanjie Qu、Taian Li、Xiaoxu Ma、Yajun Li、Hongli Bao
DOI:10.1002/anie.202017175
日期:2021.5.25
Asymmetric aminoazidation and diazidation of alkenes are straightforward strategies to build value‐added chiral nitrogen‐containing compounds from feedstock chemicals. They provide direct access to chiral organoazides and complement enantioselective diamination. Despite the advances in non‐asymmetric reactions, asymmetric aminoazidation or diazidation based on acyclic systems has not been previously
Bencyclane fumarate (I) was decomposed in aqueous buffer solution from pH 1.2 to 6.3 in order to examine its stability and mechanism of hydrolysis. It was found that I was hydrolyzed with pseudo first-order kinetics, and the pH-rate profile was a straight line of slope-1. The activation energy (Ea) was calculated to be 33.0 kcal/mol from Arrhenius plots. Further examination of the decomposition mechanism through kinetic analysis suggested a new pathway where I first formed a carbonium ion intermediate in an acidic solution then decomposed immediately into an alcohol and two olefins by hydration and dehydration, respectively.