Iridium complex-catalyzed highly selective organic synthesis

Two different synthetic reactions catalyzed by an iridium complex are discussed. The first is allylic alkylation and allylic amination. This reaction proceeds via a pi-allyl iridium intermediate. The selectivity strongly depends on the structure of the allylic esters. Highly branched product-selective allylic substitution and highly Z-selective allylic substitution were achieved. The selectivities of allylic substitution described here have not been achieved in previous studies with other transition metal complexes. The second reaction is [2+2+2] cycloaddition of alpha,omega-diynes with monoynes. This reaction proceeds via iridacyclopentadiene and tolerates various functional groups. Functionalized monoynes can be used. These results show that an iridium complex can be a useful catalyst for carbon-carbon and carbon-heteroatom bond formation.