New Regiocontrolled Synthesis of Functionalized Pyrroles from 2-Azetidinone-Tethered Allenols
作者:Benito Alcaide、Pedro Almendros、Rocío Carrascosa、María C. Redondo
DOI:10.1002/chem.200700788
日期:2008.1.7
A new one-pot approach to synthesize densely substituted racemic and enantiopure pyrrolesfrom beta-lactams has been developed. The approach relies on the regiocontrolled cyclization of beta-allenamine intermediates derived from the ring opening of 2-azetidinone-tetheredallenols. In this approach four points of diversity are introduced, one of which is the position of the allene moiety on the beta-lactam
Synthesis of a New Class of<i>C</i><sub>2</sub>-Symmetrical Biheteroaryls by Ammonium Cerium(IV) Nitrate Mediated Dimerization of 2-(Furan-3-yl)pyrroles
Polyfunctionalized 2-(furan-2-yl)pyrroles and 2-(furan-3-yl)-pyrroles derivedfrom 2-azetidinone-tethered allenes by two independent cerium(IV)-mediated single-electron oxidations provided a (4-oxopent-2-enoyl)pyrrole and 3,3'-bis(pyrrol-2-yl)-2,2'-bifurans, respectively. Access to the oxidation precursors was achieved by regiocontrolled cyclization of β-al-lenamine intermediates derivedfrom selective β-lactam