Synthesis of Cyclic Ethers Utilizing a Cyclization–Fragmentation Strategy
作者:Denise A. Ockey、David R. Lane、Juliette A. Seeley、Neil E. Schore
DOI:10.1016/s0040-4020(99)01063-7
日期:2000.1
A variety of cyclic ethers have been prepared via both solution phase and polymer-supported sequences of 3+2 cycloaddition of nitrile oxides to alkenes and dienes to give isoxazolines, followed by electrophile-induced cyclization. Library generation by alkylative elaboration of isoxazolines was unsuccessful, but both simple and substituteddienes were found suitable for polymer-supported formation
Iron(III) chloride-catalyzed effective allylation reactions of aldehydes with allyltrimethylsilane
作者:Tsutomu Watahiki、Takeshi Oriyama
DOI:10.1016/s0040-4039(02)02107-x
日期:2002.12
Iron(III) chloride-catalyzed allylation reactions of a variety of aldehydes with allyltrimethylsilane proceeded efficiently and smoothly to afford the corresponding homoallylalcohols in high to excellent yields. This novel method could be suitable especially for the allylation of sterically hindered aliphatic aldehydes.
Trimethylsilyl bis(trifluoromethanesulfonyl)amide is shown to be an effective catalyst not only for the Friedel-Crafts alkylation of an aromatic compound but also for allylation or bis-allylation of carbonyl derivatives.
allylation product in the presence of a catalytic amount of the (cyclooctadiene)rhodium(I) chloride dimer [Rh(cod)Cl]2}, sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (NaBARF), and triphenyl phosphite [P(OPh)3] in refluxing 1,2-dichloroethane. Primary, secondary and tertiary benzyl acetates could be used for the reaction. Moreover, allylation of gem-benzyl acetate was possible with [Rh(cod)Cl]2, NaBARF
Deoxygenative Allylation of Benzyl Acetates and Cinnamyl Alcohols Catalyzed by Molecular Iodine
作者:J. S. Yadav、B. V. Subba Reddy、A. Srinivas Reddy、B. Eeshwaraiah
DOI:10.1246/cl.2007.1500
日期:2007.12.5
Benzyl acetates undergo smooth deoxygenative allylation with allyltrimethylsilane in the presence of 10 mol % of molecular iodine under mild conditions to afford the corresponding allyl derivatives in excellent yields and with high selectivity. Cinnamyl alcohols also react readily with allylsilane under similar conditions. The use of molecular iodine makes this method quite simple, more convenient