Polarizing the Nazarov Cyclization: The Impact of Dienone Substitution Pattern on Reactivity and Selectivity
作者:Wei He、Ildiko R. Herrick、Tulay A. Atesin、Patrick A. Caruana、Colleen A. Kellenberger、Alison J. Frontier
DOI:10.1021/ja077162g
日期:2008.1.1
The impact of dienone substitution on the Nazarovcyclization has been examined in detail. Substrates bearing different substituents at each of four positions on the dienone backbone were systematically probed in order to identify trends leading to higher reactivity and better selectivity. Desymmetrization of the pentadienyl cation and oxyallyl cation intermediates through placement of polarizing groups
A torquoselective extrusion of isoxazoline N-oxides. Application to the synthesis of aryl vinyl and divinyl ketones for Nazarov cyclization
作者:Daniel P. Canterbury、Ildiko R. Herrick、Joann Um、K.N. Houk、Alison J. Frontier
DOI:10.1016/j.tet.2008.10.003
日期:2009.4
A mild, convenient reaction sequence for the synthesis of Nazarov cyclization substrates is described, The [3+2] dipolar cycloaddition of a nitrone and an electron-deficient alkyne gives all isolable isoxazoline intermediate, which upon oxidation undergoes stereoselectivc extrusion of nitrosomethane to give aryl vinyl or divinyl ketones. (C) 2008 Elsevier Ltd. All right, reserved.
Studies toward the AB ring system of the tetrapetalone natural products
作者:Peter N. Carlsen、Chao Jiang、Ildiko R. Herrick、Alison J. Frontier
DOI:10.1016/j.tet.2015.05.021
日期:2015.9
Synthetic efforts toward the rapid assembly of the ABringsystem of the tetrapetalones is described. Key to this work was the use of [3+2] cycloaddition/oxidative extrusion methodology to furnish functionalized aryl enones. The Nazarov cyclization of these substrates was examined, and optimized to generate the ABring carbon skeleton. Then, Pd-catalyzed cross-coupling were conducted, and conditions