Tandem oxidative radical brominative addition of activated alkynes and spirocyclization: switchable synthesis of 3-bromocoumarins and 3-bromo spiro-[4,5] trienone

• Published in: ORGANIC CHEMISTRY FRONTIERS Vol. 3; no. 4; pp. 510 - 515
• Main Authors: Qiu, Guanyinsheng, Liu, Tong, Ding, Qiuping
• Format: Journal Article
• Language: English
• Published: TAIPEI Chinese Chemical Soc 01.01.2016
• Subjects: Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; MEDICINAL CHEMISTRY; ALKYNOATES; ORGANIC-SYNTHESIS; FACILE APPROACH; INTRAMOLECULAR IPSO-HALOCYCLIZATION; BIOLOGICAL-ACTIVITY; CARBONYL-COMPOUNDS; BOND FORMATION; CYCLIZATION; COUMARIN DERIVATIVES

A K2S2O8-mediated tandem radical brominative addition of alkynoates, oxidative spiro-cyclization, and 1,2-migration of esters is reported for the synthesis of 3-bromocoumarins with high efficiency. The prepared 3-bromocoumarins are successfully converted into 3-alkynyl and 3-phosphite coumarins unde...