We demonstrate that a single Rh(I) complex can promote two mechanistically distinct C–C bond-forming reactions – alkyne hydroacylation and aryl boronic acid conjugate addition – to deliver substituted ketone products from the controlled assembly of three readily available fragments. This is a rare example of a Rh(I)/Rh(III) cycle and a redox neutral Rh(I)… (More)
A Rh-catalyst system based on the asymmetric ligand (t)Bu2PCH2P(o-C6H4OMe)2 is reported that allows for the hydroacylation of challenging internal alkenes with β-substituted aldehydes. Mechanistic studies point to the stabilizing role of both excess alkene and the OMe-group.
We have developed an efficient procedure for the easy and straightforward preparation of functionalized dihydropyridazines as highly enantiopure materials by reaction of pyruvaldehyde 2-tosyl hydrazone with a variety of α,β-unsaturated aldehydes using a chiral secondary amine as catalyst. The overall process consists of a cascade reaction involving an… (More)
The conformational flexibility of the linkage mechanism or tether between paramagnetic metal centers is explored to assess optimal structural characteristics of multimeric MRI contrast agents. Two dimeric paramagnetic chelates differing in linkage flexibility but similar in symmetry are compared Relaxivity, water hydration number, and reorientational times… (More)