Photochemical Cyclization with Release of Carboxylic Acids and Phenol from Pyrrolidino-Substituted 1,4-Benzoquinones Using Visible Light
作者:Yugang Chen、Mark G. Steinmetz
DOI:10.1021/ol051362k
日期:2005.8.1
rolidino-1,4-benzoquinones effects photoisomerization to labile oxazolidines, which undergo elimination of carboxylate or phenolate leaving groups in high yields to generate trappableo-quinone methide intermediates. [reaction: see text]
Photoactivation of Amino-Substituted 1,4-Benzoquinones for Release of Carboxylate and Phenolate Leaving Groups Using Visible Light
作者:Yugang Chen、Mark G. Steinmetz
DOI:10.1021/jo060790g
日期:2006.8.1
a dark reaction. Lifetimes for elimination of 4-YC6H4OH in 30% phosphate buffer in CD3CN (pD 7) at 17 °C are 13.1, 0.54, and 0.13 h for Y = H, CF3, and CN, respectively, and the linear equation log k (h-1) = 0.998(−pKa) + 8.80 gives a best fit to the data. Carboxylate leaving groups are rapidly eliminated upon photolysis of the quinones in aq CH3CN to produce an o-quinone methide intermediate that is