91110-38-2Relevant articles and documents
Reaction of terminal phosphinidene complexes with enamines. A method for inserting a phosphinidene unit into a carbonyl-activated C-H bond
Marinetti, Angela,Mathey, Franco?is
, p. 1492 - 1495 (2008/10/08)
The reactions of a phosphanorbomadienic precursor for (phenylphosphinidene)pentacarbonyltungsten with enamines at 115-120°C give three types of products according to the choice of the enamine. With 1-morpholinoisobutene, the expected phosphirane is obtained and can be hydrolyzed by hot water to give [α-(phenylphosphino)isobutyraldehyde]pentacarbonyltungsten. With a series of morpholinoalkenes derived from cyclohexanone, cyclopentanone, paramethylacetophenone, and isovaleraldehyde, the transient phosphirane cannot be observed and the final product results from an insertion of the (phenylphosphinidene)pentacarbonyltungsten unit into one of the carbon-hydrogen bonds adjacent to the carbonyl group of the starting ketone or aldehyde. In one particular case, the intermediate phosphirane rearranges to give an open-chain enamine with a (phenylphosphino)pentacarbonyltungsten substituent. These various observations can be rationalized if we assume that the 1:1 phenylphosphinidene-enamine adduct is not a classical phosphirane but has a partly zwitterionic, open-chain structure.
