Palladium-catalyzed aryl halide carbonylation-intramolecular O-enolate acylation: efficient isocoumarin synthesis, including the synthesis of thunberginol A.
Exposure of a series of ?-(o-haloaryl)-substituted ketones to palladium-catalyzed carbonylation conditions leads to the formation of the corresponding isocoumarins. Balloon pressure of CO is sufficient to achieve high yielding reactions, and both cyclic and acyclic ketones are efficient substrates. The utility of the method is illustrated by a short synthesis of the natural product thunberginol A.
Tadd
Andrew C
AC
University of Oxford, Chemical Research Laboratory, Mansfield Road, Oxford, UKOX1 3TA.
Fielding
Mark R
MR
Willis
Michael C
MC
D000215:Acylation; D002248:Carbon Monoxide; D002384:Catalysis; D049934:Isocoumarins / Q000138:chemical synthesis*; D007659:Ketones / Q000737:chemistry; D055601:Organic Chemistry Phenomena; D010165:Palladium / Q000737:chemistry*
D049934:Isocoumarins; D007659:Ketones; C079055:thunberginol A; D010165:Palladium; D002248:Carbon Monoxide