[GRAPHICS]Kinetic studies demonstrate that it is possible to achieve large rate enhancements (2 x 10(4)) for the hydrolysis of a urethane group by using metal-bound water or hydroxide as the nucleophile.
[GRAPHICS]Kinetic studies demonstrate that it is possible to achieve large rate enhancements (2 x 10(4)) for the hydrolysis of a urethane group by using metal-bound water or hydroxide as the nucleophile.
Intramolecular Pyridone/Enyne Photocycloaddition: Partitioning of the [4 + 4] and [2 + 2] Pathways
作者:Svitlana Kulyk、William G. Dougherty、W. Scott Kassel、Michael J. Zdilla、Scott McN. Sieburth
DOI:10.1021/ol200390j
日期:2011.5.6
Intramolecular photocycloaddition (>290 nm) between a 1,3-enyne and a 2-pyridone is far more selective than the intermolecular version; a three-atom linkage both controls regiochemistry and separates the [2 + 2] and [4 + 4] pathways. All four head-to-head, head-to-tail, tail-to-head, and tail-to-tail tetherings have been investigated. Linkage via the ene of the enyne leads to [2 + 2] products regardless