PPh3 and zinc metal conjugated alkenes (CH2CHCOOR, CH2CHCN, CH2CHSO2Ph and CH2CHCONEt2) undergo reductive tail-to-tail dimerization to yield the corresponding saturated linear products. Under similar reaction conditions, vinylarenes (ArCHCH2) give stereoselective head-to-tail dimerization products, trans-1,3-diarylbut-1-ene, in good to excellent yields.
Novel ruthenium-catalyzed reactions that employ ruthenium trichloride n-hydrate (RuCl3·nH2O) were investigated and dimerization, alkoxylation and sulfidation of olefins were noted. Adducts of Markovnikov type and anti-Markovnikov type were obtained in a stereospecific manner and in good yield, depending on the type of olefins used as the starting materials.
Feeding the Heck Reaction with Alcohol: One-Pot Synthesis of Stilbenes from Aryl Alcohols and Bromides
作者:Paul Colbon、Jonathan H. Barnard、Mark Purdie、Keith Mulholland、Ivan Kozhevnikov、Jianliang Xiao
DOI:10.1002/adsc.201200340
日期:2012.5.21
Aryl alcohols are employed as feedstock for the Heck reaction. Keggin‐type heteropolyacids catalyse the selective dehydration of the alcohols to styrenes, which, in one‐pot, undergo palladium‐catalysed Heck arylation with aryl bromides, affording broadly functionalised stilbenes. The choice of solvent is critical for the cascade dehydration–Heck reaction, with electron‐rich aryl alcohols preferring
Highly efficient Pd(acac)2/TFA catalyzed head-to-tail dimerization of vinylarenes at room temperature
作者:Hengchang Ma、Qiangsheng Sun、Wenfeng Li、Jinxia Wang、Zhe Zhang、Yaoxia Yang、Ziqiang Lei
DOI:10.1016/j.tetlet.2011.01.056
日期:2011.4
Pd(acac)2 catalyzed dimerization of vinylarenes to form dimers under mild condition with excellent yields and stereoselectivities. In particular, the use of TFA highly promoted the activity and selectivity of the dimerization. The studies on mechanism for the reaction displayed clearly that the dimerization of styrenes is 100% atom economic reaction.
Copper-Catalyzed Intermolecular Hydroamination of Alkenes
作者:Jason G. Taylor、Neil Whittall、King Kuok (Mimi) Hii
DOI:10.1021/ol061355b
日期:2006.8.1
Regioselective additions of arylsulfonamides to vinylarenes, norbornene, and cyclohexadiene were achieved using a copper-diphosphine catayst under mild reaction conditions. These processes appear to be ligand-accelerated.