Palladium(II)-catalyzed carbocyclization: Vinylpalladium in 1,4-oxidation of conjugated dienes
作者:Ylva I.M. Nilsson、Roberto G.P. Gatti、Pher G. Andersson、Jan-E. Bäckvall
DOI:10.1016/0040-4020(96)00265-7
日期:1996.5
containing a terminal or internal triple bond. A vinylpalladium species formed by chloropalladation of the alkyne inserts one of the double bonds of the diene in a Heck-type reaction. The addition of palladium and chloride over the triple bond is non-stereoselective while the overall 1,4-addition by carbon and chloride over the diene is highly stereoselective and occurs anti. The stereoselectivity of the
Carbon-carbon bond formation in palladium(II)-catalyzed intramolecular 1,4-oxidation of conjugated dienes
作者:Jan-E. Bäckvall、Ylva I.M. Nilsson、Pher G. Andersson、Roberto G.P. Gatti、Jinchang Wu
DOI:10.1016/s0040-4039(00)77286-8
日期:1994.8
Palladium(II)-catalyzed 1,4-oxidation of conjugateddienes involving a carbocyclization has been developed. Chloropalladation of the triple bond in a dienyne and subsequent addition of the vinylpalladium to the conjugateddiene creates a (π-allyl)palladium intermediate, which undergoes a quinone-induced chloride attack to give the product. The overall 1,4-addition of the vinylic carbon and the chloro
Diastereoselectivity in the intramolecular diels-alder reaction of dienylpropynoates
作者:David H. Birtwistle、John M. Brown、Michael W. Foxton
DOI:10.1016/s0040-4020(01)86103-2
日期:1988.1
ratio in Diels-Alderreactions of α-chiral dienes has been examined. Cycloaddition of E-3,5-hexadien-2-ol and methyl propynoate gives a mixture of all four diastereomers. Intramolecular condensation of the related ester (6) was completely regioselective however, and one stereoisomer predominated by 6.4:1. Similar results were obtained for the corresponding secondary amide, for propynoate esters of a homologous
Molecular oxygen promoted oxidative cleavage of carbon-palladium bonds — catalytic cyclization of allylic 2-alkynoates to α-alkylidine-γ-butyrolactones by a PdII complex
作者:Guoxin Zhu、Xiyan Lu
DOI:10.1016/0022-328x(95)05781-j
日期:1996.2
Molecularoxygen was used as the oxidant to promote the PdII and CuII catalyzed cyclization of acyclic allylic 2-alkynoates, yielding α-haloakylidene-gg-butyrokactones with high stereoselectivity. The stereochemitsyr of halopalladation of the carbon-carbon triple bond, 1,2-induction in the intramolecular carbon-carbon double insertion and oxidative cleavage of carbon-palladium bonds in the cyclization
The cationic rhodium(I) species derived from [Rh(COD)Cl](2) and AgSbF6 efficiently catalyze intrarnolecular [4+2] cycloadditions of ester-tethered 1,3-diene-8-yne derivatives such as 2-propynyl penta-2,4-dienoate and 2,4-pentadienyl propiolate derivatives in fluorinated alcohols. (c) 2005 Elsevier Ltd. All rights reserved.