Photostimulated reactions of vinyl phosphate esters with triorganostannides. Evidence for an SRN1 Vinylic mechanism

B CHOPA, ALICIA; V. B. DORN; A BADAJOZ, MERCEDES; M. T. LOCKHART

JOURNAL OF ORGANIC CHEMISTRY

American Chemical Society

Lugar: Washington; Año: 2004 vol. 69 p. 3801 - 3805

0022-3263

Ketones are converted into vinyl diethyl phosphate esters (VinDEP), which under photostimulation reacted with sodium trimethylstannide (1) or sodium triphenylstannide (2) in liquid ammonia affording vinylstannanes via a vinylic SRN1 mechanism. Thus, (1-phenylvinyl)DEP (3), (3,4-dihydro- 1-naphthyl)DEP (7), (3,4-dihydro-2-naphthyl)DEP (9), (E)-(1,2-diphenylvinyl)DEP (12), (E/Z)-(1- methyl-2-phenylvinyl)DEP (14) and (E)-(1-phenyl-2-methylvinyl)DEP (16) react with 1 and 2, under photostimulation, leading to the corresponding substitution products in good to excellent yields (45-89%). On the other hand, there is no reaction between (1-cyclohexenyl)DEP (5) or (1- benzylvinyl)DEP (18) with either 1 or 2, under similar conditions. These reactions appear to be strongly dependent on structural features of the vinyl phosphate since only conjugated vinyl phosphates afforded substitution products. These substitution reactions are completely regioselective and stereoconvergent. It seems to be the first example of a vinylic SRN1 process involving organotin anions as nucleophiles.