Polyfunctionalized aldehydes and dihydropyrans were prepd. from easily available functionalized 1-alkynes through a two-step silylformylation/aryl migration sequence. The silylformylation process was performed under mild exptl. conditions and affords the corresponding β-silylalkenals in high yields. The fluoride-promoted migration step occurs instantaneously with quant. conversion. The chemo-, regio- and stereoselectivity can be modulated according to the nature and the position of the functional group on the acetylene precursors. When a good leaving group is present in the ω position of the aliph. chain of the alkyne a cyclization product was obtained, while α,β-unsatd. aldehydes are generated from propargylic tosylamides.
Autori interni: | |
Autori: | Aronica, LAURA ANTONELLA; Raffa, P; Valentini, G; CAPORUSSO A., M; Salvadori, Piero |
Titolo: | Silylformylation-fluoride-assisted aryl migration of acetylenic derivatives in a versatile approach to the synthesis of polyfunctionalised compounds |
Anno del prodotto: | 2006 |
Abstract: | Polyfunctionalized aldehydes and dihydropyrans were prepd. from easily available functionalized 1-alkynes through a two-step silylformylation/aryl migration sequence. The silylformylation process was performed under mild exptl. conditions and affords the corresponding β-silylalkenals in high yields. The fluoride-promoted migration step occurs instantaneously with quant. conversion. The chemo-, regio- and stereoselectivity can be modulated according to the nature and the position of the functional group on the acetylene precursors. When a good leaving group is present in the ω position of the aliph. chain of the alkyne a cyclization product was obtained, while α,β-unsatd. aldehydes are generated from propargylic tosylamides. |
Digital Object Identifier (DOI): | 10.1002/ejoc.200500883 |
Appare nelle tipologie: | 1.1 Articolo in rivista |