1124258-91-8Relevant academic research and scientific papers
Allylic substitution for construction of a chiral quaternary carbon possessing an aryl group
Feng, Chao,Kobayashi, Yuichi
, p. 3755 - 3766 (2013/06/05)
Phenylcopper reagents derived from 2:1 PhMgBr/Cu(acac)2 and 3:1:1 PhMgBr/Cu(acac)2/ZnI2 were found to be highly reactive and regioselective in the allylic substitution of γ,γ- disubstituted secondary allylic picolinates designed for construction of a quaternary carbon, whereas the previous 2:1 ArMgBr/CuBr·Me2S reagent and that with ZnX2 were unsuccessful. The generality of the ArMgBr/Cu(acac)2 reagent was examined with enantiomerically enriched allylic picolinates, which furnished quaternary carbons with high efficiency in >92% regioselectivity and >97% chirality transfer. Two cyclohexanes with a quaternary carbon were synthesized by using these reagents.
New general method for regio- and stereoselective allylic substitution with aryl and alkenyl coppers derived from grignard reagents
Kiyotsuka, Yohei,Katayama, Yuji,Acharya, Hukuni P.,Hyodo, Tomonori,Kobayashi, Yuichi
experimental part, p. 1939 - 1951 (2009/08/07)
Allylic substitution with sp2-carbon reagents (aryl and alkenyl anions) was realized by using allylic picolinates and copper reagents derived from RMgBr and CuBr-Me2S to afford anti SN2 products regioand stereoselectively. Steric and electronic factors in the reagents and the size of the methylene substituents around the allylic moiety marginally affected the selectivity. The reaction system was compatible with alkyl reagents as well. Furthermore, the substitution was applied to construction of a quaternary center and synthesis of (-)-sesquichamaenol. Electron-withdrawing nature of the pyridyl group and chelation of the C(=O)-C5H4N to MgBr2 generated in situ were found to be responsible for the high efficiency of the substitution.
