Coinage metal amido and thiolate SNS complexes: consequences of catalyst speciation in Cu(i)-catalysed carbonyl hydroboration

Three new IPr-Ag- and -Au-SNS amido and thiolate complexes were synthesized and compared to their previously reported Cu analogues as carbonyl hydroboration catalysts (IPr = bis(2,6-diisopropylphenyl)imidazol-2-ylidene). Although these complexes showed no catalytic activity, treatment of the IPr-Ag-SNS amido complex with pinacolborane released the N-borylated ligand, (SNSMe)-N-Me-S-Bpin, (L-1-Bpin). This finding led us to reinvestigate the IPr-Cu-SNS amido precatalyst, revealing that immediate loss of L-1-Bpin converts our catalyst system to [CuH(IPr)](2).

Automated summary

Three new IPr-Ag- and -Au-SNS amido and thiolate complexes were synthesized and compared to their previously reported Cu analogues as carbonyl hydroboration catalysts. Although these complexes showed no catalytic activity, treatment of the IPr-Ag-SNS amido complex with pinacolborane released N-borylated ligand, (SNSMe)-N-Me-S-Bpin, (L-1-Bpin). This finding led to reinvestigation of the IPr-Cu-SNS amido precatalyst, revealing immediate conversion of the catalyst system to [CuH(IPr)](2) upon loss of L-1-Bpin.