Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA.
Photochem Photobiol Sci. 2012 Dec;11(12):1929-37. doi: 10.1039/c2pp25263e.
To expand on the limited number of examples that exist in the literature for the solid-state photodenitrogenation of azoalkanes, a series of crystalline 7-alkyl-2,3,7-triazabicyclo[3.3.0]oct-2-ene-6,8-diones with varying 4,4-substituents were prepared. Their photochemical behavior in solution and in the solid state was dependent on the 4,4-substitution of the 1-pyrazoline ring, with unsubstituted pyrazoline giving a mixture of products both in solution and in the solid state. Diphenyl substituted pyrazolines denitrogenate spontaneously in solution but require light exposure to react quantitatively in the solid state. t-Butyl-phenyl substituted pyrazolines were shown to denitrogenate both chemo- and diastereoselectively in solution and in the solid state to yield a single product in quantitative yield.
为了扩展文献中存在的有限数量的实例，研究了一系列具有不同 4,4-取代基的结晶 7-烷基-2,3,7-三氮杂双环[3.3.0]辛-2-烯-6,8-二酮的固态光氮还原反应。它们在溶液和固态中的光化学反应行为取决于 1-吡唑啉环的 4,4-取代基，未取代的吡唑啉在溶液和固态中都会产生混合物产物。二苯基取代的吡唑啉在溶液中会自发地进行脱氮反应，但需要光照才能在固态中定量反应。叔丁基-苯基取代的吡唑啉在溶液和固态中都表现出化学和立体选择性的脱氮反应，以定量产率得到单一产物。
