Photoinduced Reactions of 1-Acetylisatin with Phenylacetylenes
作者:Jie Xue、Yan Zhang、Xiao-long Wang、Hoong Kun Fun、Jian-Hua Xu
DOI:10.1021/ol000110a
日期:2000.8.1
[GRAPHICS]Photoinduced reactions of 1-acetylisatin 1 with diphenylacetylenes 2a-2c afforded the corresponding 3-methylene-2-indolones 4a-4e and 5a-5e in 80-90% yields via a spirooxetene intermediate, Similar irradiation of 1 with phenylacetylene, on the other hand, resulted in efficient formation of two diastereoisomeric dispiro[3H-indole-3,2'-furan-3',3"-(3H)-indole]-2,5',2"(2H,5'H,2"H)triones 6 and 7 via a reaction sequence with initial formation of the spirooxetene intermediate. The regioselectivity in the photocycloaddition of 1 with phenylacetylene and the reaction mechanism for the formation of 6 and 7 are discussed.
Photoreactions of 1-Acetylisatin with Alkynes: Regioselectivity in Oxetene Formation and Easy Access to 3-Alkylideneoxindoles and Dispiro[oxindole[3,2‘]furan[3‘,3‘ ‘]oxindole]s
作者:Lei Wang、Yan Zhang、Hua-You Hu、Hoong Kun Fun、Jian-Hua Xu
DOI:10.1021/jo047870+
日期:2005.5.1
the C(O)−H functionality in IV followed by dissociation of the triplet isatin ketyl (A)−aldehyde acyl (B) radical pair and an oxygenphilic attack of the acyl radical B at the C3 carbonyl oxygen atom of a neutral IS gave the 2:1 (IS:4) radical C, which took part in an intramolecular radical cyclization to give the dispiroindole[3,2‘]furan[3‘,3‘ ‘]indoles 13 and 14. The regioselectivity in the [2+2] photocycloadditions
1-acetylisatin(IS)与diphenylacetylenes的光诱导反应1A - Ç,1-(p -甲氧基苯基)丙炔2,和1,4-二苯基-1,3-丁二炔3,得到β,β二取代-3-亚烷基羟吲哚6 -通过炔和随后的氧杂环丁烯开环分别通过3 IS *的[2 + 2]环加成12。IS与苯基乙炔4a - d和环丙基乙炔5的光反应提供了双螺吲哚[3,2']呋喃[3',3'']吲哚13和14。化合物13和14是在串联反应中形成的,该反应由3 IS *与炔烃的[2 + 2]环加成反应生成螺环氧杂环戊烯Va和Vb,自发开环后得到α,β-不饱和醛IVa和IVb。所以建议的夺氢3 IS *从C(O)-H在功能IV随后三重态靛红羰游基(解离阿) -醛酰基(乙)基团对和酰基的oxygenphilic攻击乙在中性IS的C3羰基氧原子上产生2:1(IS:4)自由基C,该自由基C参与分子内自由基环化反应生成dispiroindole