57213-25-9Relevant academic research and scientific papers
Installation of a chiral side chain to a 2-alkylidene-1-cycloalkan-1-ol unit by using allylic substitution
Feng, Chao,Kobayashi, Yuichi
, p. 6666 - 6676 (2013/11/06)
The allylic substitution of optically active exocyclic allylic esters of cyclopentane and cyclohexane with ArMgBr-based copper reagents (Ar = aryl) was examined. ArMgBr/Cu(acac)2 in a 2:1 ratio was an adequate reagent to produce the anti-SN2' products efficiently in terms of regioselectivity (95-99a€‰%), chirality transfer (91-99a€‰%), and yield (71-91a€‰%). The Ar groups that were successfully installed include Ph and p-tolyl, those with electron-donating (i.e., p-MeOC6H4) and electron-withdrawing groups (i.e., p-FC6H4), and those with sterically demanding groups (i.e., o-tolyl, o-MeOC6H 4). In an examination of an alkyl reagent, BuMgBr/CuBr·Me 2S in a 2:1 ratio in the presence of ZnI2 afforded the product with high regioselectivity (99a€‰%) and in good yield (91a€‰%). The allylic substitution of exocyclic allylic picolinates (n = 1, 2; R = Ph(CH2)2, iPr, Ph) with a ArCu(acac)MgBr reagent (Ar = Ph, p-tolyl, p-MeOC6H4, p-FC6H4, o-tolyl, o-MeOC6H4) that was derived from a 2:1 ratio of ArMgBr and Cu(acac)2 efficiently afforded the anti-SN2' products in terms of regioselectivity (95-99a€‰%), chirality transfer (91-99a€‰%), and yield (71-91a€‰%). Copyright
RADICAL β-FRAGMENTATION OF BICYCLOCARBINOLAMIDES: SYNTHESIS OF FIVE- AND EIGHT-MEMBERED CYCLIC IMIDES
Hernandez, Rosendo,Melian, Daniel,Prange, Thierry,Suarez, Ernesto
, p. 439 - 454 (2007/10/02)
The influence of 4-alkyl or 4-aryl substituents in the regioselectivity of the β-fragmentation of carbinolamidyl radicals generated from the corresponding carbinolamides (7-13) by irradiation with visible light in the presence of (diacetoxyiodo)benzene an
Regio- and Stereoselective Cross-aldol Reactions via Dialkylboryl Triflates
Inoue, Tan,Mukaiyama, Teruaki
, p. 174 - 178 (2007/10/02)
New borylating reagents, (Bu2BOTf and 9-BBNOTf), were prepared in high yields.The triflates reacted with enolizable ketones in the presence of tertiary amines to generate selectively one of the regioisomers of vinyloxyboranes by the choice of the reagents (the dialkylboryl triflates and tertiary amines) under mild reaction conditions.Vinyloxyboranes thus generated showed remarkable reactivity toward aldehydes to give only one regioisomer of the corresponding cross-aldols in good yields.High stereoselectivity was also observed in these reactions.
