Reaction of 2-Benzoselenopyrylium Salts with Nucleophiles: Formation of 1-Functionalized Isoselenochromenes
摘要:
1-Unsubstituted isoselenochromenes (3) were converted into the 2-benzoselenopyrylium salts (4) by treatment with Ph3C+BF4- and the reaction of the salts (4) with several nucleophilic reagents (alcohol, amine, cyanide, acetone, and Grignard reagents) afforded the corresponding 1-functionalized isoselenochromenes (5-9) in high yields, respectively. 1-Alkyl- and 1-phenyl-2-benzoselenopyrylium salts (10) were also obtained from 9.
Reaction of 2-Benzotelluropyrylium Salts with Organocopper Reagents: Introduction of a Carbon Functional Group at the C-1 Position of the Telluropyrylium Cation Ring
作者:Haruki Sashida、Hirohito Satoh、Kazuo Ohyanagi
DOI:10.3987/com-03-9944
日期:——
3-tert-Butyl-2-benzotelluropyrylium salt (13A) react with lithium dialkyl(phenyl)copper to give in good yield the corresponding isotellurochromenes (15A) having a carbon functional group at the C-1 position. Similarly, the 1-substituted isoselenochromenes (15B) and the 4-substituted tellurochromene (19) were also prepared from the corresponding pyrylium salts (13B, 18). The obtained isotellurochromenes (15A) were easily converted into the corresponding 2,4-disubstituted 2-benzotelluropyrylium salts (20) by the treatment with triphenylcarbenium tetrafluoroborate (Ph3C+ BF4-).