Lewis Acid Mediated Intramolecular C–C Bond Formation of Alkyne-Epoxide Leading to Six-Membered Nitrogen and Oxygen Heterocycles
作者:Priya Ghosh、Pipas Saha、Somasekhar Bondalapati、Kiran Indukuri、Anil K. Saikia
DOI:10.1021/jo402550e
日期:2014.5.2
Intramolecular C–C bond formation of oxygen- and nitrogen-tethered alkynes and epoxide mediated by Lewis acid under ambient conditions is described. A simple procedure for the synthesis of 3,6- and 5,6-dihydropyrans and 3,4-dehydropiperidines from acyclic building blocks in good yields without using any transition metal is shown.
Radical Cyclizations Terminated by Ir-Catalyzed Hydrogen Atom Transfer
作者:Andreas Gansäuer、Matthias Otte、Lei Shi
DOI:10.1021/ja109362m
日期:2011.1.26
A system for coupling catalytic radical cyclization and Ir-catalyzed hydrogen atom transfer (HAT) is described. It is essential that the HAT catalyst activates H(2) quickly and is not a hydrogenation catalyst. Vaska's complex was found to fulfill both purposes efficiently.