211449-26-2Relevant articles and documents
Directed ortho metalation-cross coupling links. Carbamoyl rendition of the Baker-Venkataraman rearrangement. Regiospecific route to substituted 4- hydroxycoumarins
Kalinin, Alexey V.,Da Silva, Alcides J. M.,Lopes, Claudio C.,Lopes, Rosangela S. C.,Snieckus, Victor
, p. 4995 - 4998 (2007/10/03)
A new carbamoyl Baker-Venkataraman rearrangement (4) which allows a general synthesis of substituted 4-hydroxycoumarins 8 in 43-82% overall yields is described; the intermediate arylketones 6 are efficiently prepared (59-91% yields) via a Directed ortho Metalation - Negishi cross coupling protocol from arylcarbamates 5 and the overall sequence provides a regiospecific anionic Friedel-Crafts complement for the construction of ortho-acyl phenols and coumarins.