Expanding the Scope of the Diels-Alder Reaction: Development of Cationic Dienophiles Stabilized by Cobalt-Complexed Alkynes Kevin M. Shea, Department of Chemistry, Smith College, Northampton, MA (CO)3 Co Ph
(CO)3 Co Co(CO)3
O
O
Ph BF3 OEt2
SiMe3
F 3B
O
O
Ph
Ph Co(CO)3
(CO)3 Co
SiMe3
O 59%
O
(CO)3 Co
or O
Co(CO)3
O
SiMe3
Co(CO)3 SiMe3
Diels-Alder reactions of cationic dienophiles stabilized by cobalt-complexed alkynes show greatly enhanced reactivity versus the corresponding substrates lacking cobalt complexation. Studies are currently underway to determine the regio- and stereoselectivity of these novel dienophiles. Ph
(CO)3 Co Ph
(CO)3 Co Co(CO)3
O
O
(CO)3 Co
SiMe3
Ph BF3 OEt2
O O
Co(CO)3 F 3B
O
O
SiMe3
Co(CO)3 SiMe3
or Ph
59%
(CO)3 Co O O
Co(CO)3 SiMe3
