Rhodium-catalyzed intramolecular hydroacylation of 5- and 6-alkynals: convenient synthesis of alpha-alkylidenecycloalkanones and cycloalkenones.
A novel intramolecular hydroacylation of 5- and 6-alkynals leading to alpha-alkylidenecycloalkanones was accomplished by using cationic a rhodium(I)/BINAP complex. For all cyclizations described, a single (E)-olefin isomer was obtained. At elevated temperature, hydroacylation and double bond migration of 5- and 6-alkynals proceeded in a one-pot reaction to give cycloalkenones. An intramolecular hydroacylation of a 7-alkynal was unsuccessful. This method represents an attractive new route to highly functionalized alpha-alkylidenecycloalkanones and cycloalkenones.
Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.
Kenzo
K
Takeishi
Koudai
K
Sugishima
Kaori
K
Sasaki
Ken
K
Tanaka
D000215:Acylation; D000447:Aldehydes / Q000138:chemical synthesis / Q000737:chemistry*; D000473:Alkanes / Q000138:chemical synthesis / Q000737:chemistry*; D000478:Alkylation; D002384:Catalysis; D002412:Cations / Q000737:chemistry; D003500:Cyclization; D006900:Hydroxylation; D015394:Molecular Structure; D012238:Rhodium / Q000737:chemistry*
D000447:Aldehydes; D000473:Alkanes; D002412:Cations; D012238:Rhodium