New synthetic applications of indium organometallics in cross-coupling reactions.

The use of indium organometallics in multifold and sequential cross-coupling reactions is reported. Triorganoindium reagents (R₃In) react, under palladium catalysis, with oligohaloarenes affording the multiple cross-coupling products in a single operation. In the reaction, the three organic groups (alkyl, aryl, alkenyl or alkynyl) attached to indium are efficiently transferred to the electrophile, with only a slight excess of organometallic reagent. We demonstrate that indium organometallics are useful reagents for sequential cross-coupling reactions. This reaction illustrates the high chemoselectivity of R₃In.