Photoinduced reactions of 1-acetylisatin with phenylacetylenes.
[reaction: see text]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.
Xue
J
J
Department of Chemistry, Nanjing University, People's Republic of China.
Zhang
Y
Y
Wang
X I
XI
Fun
H K
HK
Xu
J H
JH
D000114:Acetylene / Q000031:analogs & derivatives* / Q000737:chemistry; D018360:Crystallography, X-Ray; D007202:Indicators and Reagents; D007510:Isatin / Q000031:analogs & derivatives* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D010777:Photochemistry
D007202:Indicators and Reagents; C044736:phenylacetylene; C414384:1-acetylisatin; D007510:Isatin; D000114:Acetylene