School of Chemistry and Chemical Engineering, Key Lab of Analytical Chemistry for Life Science, Ministry of Education of China, Nanjing University, Nanjing, 210093, P. R. China.
J Org Chem. 2010 May 7;75(9):2989-3001. doi: 10.1021/jo100218w.
Photoinduced tandem reactions of isoquinoline-1,3,4-triones (3) with azaaryl substituted acetylenes (4a-4o) are described as an efficient method to build novel aza-polycycles. Most of the reactions proceeded via the tandem reaction sequence of photoinduced [2 + 2] cycloaddition (the Paterno-Büchi reaction)-oxetene electrocyclic ring opening-hexatriene to phenanthrene type electrocyclization-oxidative dehydrogenation. Using these photo tandem reactions of isoquinolinetrione with acetylenes substituted by different azaaryl rings including pyridine, pyrimidine, pyrazine, and quinoline, we were able to obtain diverse aza-polycyclic frameworks with isoquinolinedione fused with naphthalene, quinoline or isoquinoline, quinazoline, quinoxaline, and phenanthridine, respectively, with yields up to 85%. Regioselectivity of the [2 + 2] photocycloadditions and the electrocyclization reactions in the reaction sequence that leads to the formation of different aza-polycyclic ring systems is discussed. Changing the other substitution group on the azaaryl substituted acetylenes from benzene to pyridine or cyclopropane resulted in acetylenes with different photoreactivities with isoquinolinetrione and improved regioselectivity to form single aza-polycyclic products.
本文描述了异喹啉-1,3,4-三酮（3）与氮芳基取代的炔烃（4a-4o）的光诱导串联反应，这是构建新型氮杂多环的有效方法。大多数反应通过光诱导[2+2]环加成（Paterno-Büchi 反应）-环氧开环-六烯到菲并型电环化-氧化脱氢的串联反应序列进行。通过使用这些带有不同氮芳基环（包括吡啶、嘧啶、吡嗪和喹啉）取代的炔烃与异喹啉-1,3,4-三酮的光串联反应，我们能够获得具有异喹啉二酮与萘、喹啉或异喹啉、喹唑啉、喹喔啉和菲啶分别融合的不同氮杂多环骨架，产率高达 85%。讨论了反应序列中导致形成不同氮杂多环体系的[2+2]光环加成和电环化反应的区域选择性。将氮芳基取代的炔烃上的其他取代基从苯变为吡啶或环丙烷，会导致与异喹啉-1,3,4-三酮具有不同光反应性的炔烃，并提高形成单一氮杂多环产物的区域选择性。
