Carbopalladation ketone trapping

The aminopalladation and subsequent carbonylation proceed smoothly. The aminopalladation of one of the double bonds of allene 129 generates 130, and CO insertion affords the ester 131 [96]. The carbopalladation of the optically active N-vinyl carbamate 132 with malonate afforded 133. Then CO insertion and trapping with vinylstannane produced the ketone 134 with 95% de, which was converted to 135 [97]. 

In contrast to the diverse insertion chemistry of vinylpalladium intermediates discussed in Sects. IV.3 and IV.5, the reactions of vinylpalladium complexes with electrophiles had not been reported until recently. Although a single report on the annulation of the o-mer-curio benzaldehyde with diphenylacetylene into the corresponding indenols and inde-nones catalytic in palladium and stoichiometric in copper had been communicated in 1992, the more synthetically useful protocol for the catalytic version of this type of transformation remained unknown until 1999. In this section the intermolecular carbopalladation of alkynes with aryl halides followed by the intramolecular trapping of the formed vinylpalladium species with ketones, aldehydes, and nitriles will be discussed. 

B. CARBOPALLADATION OF ALKYNES FOLLOWED BY TRAPPING WITH KETONES. 

---