An efficient method for conversion of 1-alken-3-yl carbonates to 1-alkenes and 3-chloro-1-alkenes via allyltitaniums
摘要:
Hydrolysis and halogenolysis of the allyltitaniums derived from allylic carbonates and a Ti(O-i-Pr)(4) / 2 i-PrMgCl reagent proceed with high regio- and stereoselectivity, thus providing an efficient method for converting 1-alken-3-yl carbonates to l-alkenes or 3-chloro-1-alkenes. (C) 1998 Elsevier Science Ltd. All rights reserved.
allyl ethyl carbonates with isocyanides in the presence of a catalytic amount of Pd(OAc)2 provided ketenimines through β‐hydride elimination of the allyl imidoylpalladium intermediates. The insertion of the isocyanide into the π‐allyl Pd complex proceeded via an unusual η1‐allyl Pd species. The resulting ketenimines were hydrolyzed to β,γ‐unsaturated carboxamides during purification by flash column chromatography
The catalytic allylic difluoromethylation of allyl carbonates with (difluoromethyl)zinc reagent, which can be readily prepared via iodine-zinc exchange reaction of difluoroiodomethane with diethylzinc, was achieved by employing copper salt as a catalyst. The difluoromethylation proceeded with not only good-to-high yields but also complete regioselectivity. Furthermore, the reaction was demonstrated
Nickel(0)-catalyzed Reaction of<i>O,O</i>-Dialkyl Phosphonates with Allyl Acetates or Carbonates. A Novel Method of Preparing Allyl Phosphonates
作者:Xiyan Lu、Jingyang Zhu
DOI:10.1055/s-1986-31704
日期:——
Allyl phosphonates are synthesized in good yield by the reaction of allyl acetates or carbonates with O,O-dialkyl phosphonates under the catalysis of Ni(cod)2 in the presence of O,N-bis(trimethylsilyl)acetamide(BSA).
enantioselective allylicamination of acyclic allylic carbonates catalyzed by a palladium/(S)-BINAP(S) system was investigated. Amination of several substrates proceeded with high ee. Crotyl carbonates show an unusually high regioselectivity for the branched isomer. The use of (S)-TolBINAP(S) and (S)-3,5-xylyl-BINAP(S) as ligands was found to increase the enantioselectivity of the aminations. A P,S binding
Synthetic Applications of the Carbanion with a Fluoroalkyl Group Generated by Palladium(0) Catalyst under Neutral Conditions
作者:Yuzo Komatsu、Toru Sakamoto、Tomoya Kitazume
DOI:10.1021/jo990463r
日期:1999.10.1
fluorine atom(s) are described. Palladium(0)-catalyzedallylation reactions under neutral conditions proceeded smoothly in the system where a methylene group is activated by fluoroalkyl and carbonyl groups. In the above systems, the 2,2,2-trifluoroethyl moiety has been introduced onto the allylic position without the release of fluoride. Further, palladium(0)-catalyzed heterocyclization was achieved