Cationic cyclizations initiated by electrocyclic cleavage of cyclopropanes. Synthesis of lactones, tetrahydropyrans, and tetrahydrofurans
作者:Rick L. Danheiser、John M. Morin、Melvin Yu、Ajoy Basak
DOI:10.1016/s0040-4039(01)82105-5
日期:——
The electrocyclic opening of cyclopropanederivatives containing internal nucleophilic groups provides a new route to vinyl lactones, tetrahydropyrans, and tetrahydrofurans.
Palladium-catalyzed intramolecular 1,2-oxidation of allenes
作者:Catrin Jonasson、Jan-E. Bäckvall
DOI:10.1016/s0040-4039(98)00559-0
日期:1998.5
Palladium(II)-catalyzedintramolecular 1,2-oxidation of allenic acids proceeds smoothly under mild conditions in the presence of LiBr and p-benzoquinone to give bromolactones in good to high yields.
Gold(i)-catalyzed enantioselective bromocyclization reactions of allenes
作者:Dillon H. Miles、Marcos Veguillas、F. Dean Toste
DOI:10.1039/c3sc50811k
日期:——
The enantioselective bromocyclization of allenes is accomplished through the use of a chiral dinuclear gold complex and/or chiral phosphate anions in the presence of an N-bromolactam as an electrophilic bromine source. This method provides access to heterocyclic vinyl bromides with an allylic stereocenter in excellent yield and enantioselectivity. These enantioenriched vinyl bromides may serve as a