Recognition-Mediated Facilitation of a Disfavored Diels−Alder Reaction
作者:Raphaël Bennes、Douglas Philp、Neil Spencer、Benson M. Kariuki、Kenneth D. M. Harris
DOI:10.1021/ol9908880
日期:1999.10.1
[GRAPHICS]The rational design of a system which is capable of accelerating and facilitating a thermodynamically disfavored Diets-Alder cycloaddition between a furan and a maleimide is presented. The origins of the acceleration and facilitation of the cycloaddition reaction are traced by kinetic studies-allied to results from H-1 NMR spectroscopy and X-ray crystallography-to the formation of strong intramolecular hydrogen bonds in the cycloadduct.
Probing Selectivity in Recognition-Mediated Dynamic Covalent Processes
作者:Raphael M. Bennes、Douglas Philp
DOI:10.1021/ol061177m
日期:2006.8.1
[reaction: see text] Two simple recognition-mediated dynamic Diels-Alder systems are used to probe the role of kinetics and thermodynamics in determining the equilibrium position in exchanging libraries and the time taken to reach that equilibrium. The selectivity expressed by recognition-driven dynamicprocesses is demonstrated to be less than the free-energy difference between the components as a