Substrate-Selective Catalysis and CCC-Pincer LigandsAnthony R. Chianese, Department of Chemistry, Colgate University

Sendritic, bowl-shaped N-heterocyclic carbene ligands G0-G2 were synthesized to demonstrate substrate specificity based on size and shape in

iridium-catalyzed ketone hydrosilylation:

Ligand

0

0.5

1

1.5

2

2.5

3

3.5

4

11a vs. 11b 11a vs. 11c 11a vs. 11d

Rel

ativ

e In

itia

l Rat

es

G0

G1

G2

Substrate Specificity

G2

G1

G0

Aryl-substituted CCC-pincer ligands were synthesized, and metalation to iridium gives solvated

hydridochloride complexes that may be useful for homogeneous catalysis, including C-H functionalization and hydroamination

X-ray structure: Ar = mesityl