Aspartyl β-Turn-Based Dirhodium(II) Metallopeptides for Benzylic C(sp)-H Amination: Enantioselectivity and X-ray Structural Analysis.

Amination of C(sp)-H bonds is a powerful tool to introduce nitrogen into complex organic frameworks in a direct manner. Despite significant advances in catalyst design, full site- and enantiocontrol in complex molecular regimes remain elusive using established catalyst systems. To address these challenges, we herein describe a new class of peptide-based dirhodium(II) complexes derived from aspartic acid-containing β-turn-forming tetramers.

Site-Selective Nitrene Transfer to Conjugated Olefins Directed by Oxazoline Peptide Ligands.

Site-selective nitrene transfer to di- and polyene substrates has been achieved using designed peptide-embedded bioxazoline ligands capable of binding copper. In model 1,3-diene substrates, the olefinic position proximal to a directing group was selectively functionalized. Additional studies indicate that this selectivity stems from non-covalent substrate-catalyst interactions.

Catalytic Dibenzocyclooctene Synthesis via Cobalt(III)-Carbene Radical and ortho-Quinodimethane Intermediates.

The metalloradical activation of ortho-benzallylaryl N-tosyl hydrazones with [Co(TPP)] (TPP=tetraphenylporphyrin) as the catalyst enabled the controlled exploitation of the single-electron reactivity of the redox non-innocent carbene intermediate. This method offers a novel route to prepare eight-membered rings, using base metal catalysis to construct a series of unique dibenzocyclooctenes through selective C -C cyclization. The desired eight-membered-ring products were obtained in good to excellent yields.

Coulomb couplings in solubilised light harvesting complex II (LHCII): challenging the ideal dipole approximation from TDDFT calculations.

The light harvesting complex II (LHCII), is a pigment-protein complex responsible for most of the light harvesting in plants. LHCII harvests sunlight and transfers excitation energy to the reaction centre of the photo-system, where the water oxidation process takes place. The energetics of LHCII can be modulated by means of conformational changes allowing a switch from a harvesting to a quenched state.