Asymmetric Olefin Isomerization of Butenolides via Proton Transfer Catalysis by an Organic Molecule

Protonation of silylenol ether via excited state proton transfer catalysis.

We demonstrate the photocatalytic protonation of a silylenol ether using 7-bromo-2-naphthol as an ESPT catalyst with phenol as the sacrificial proton source. Greater than 95% conversion is achieved with 1 mol% catalyst. The reaction cycle is dependent on the significantly increased acidity of the catalyst in the excited state as well as the long lifetime for the triplet excited state of 7-bromo...

Catalytic Olefin Hydroamidation Enabled by Proton-Coupled Electron Transfer

Here we report a ternary catalyst system for the intramolecular hydroamidation of unactivated olefins using simple N-aryl amide derivatives. Amide activation in these reactions occurs via concerted proton-coupled electron transfer (PCET) mediated by an excited state iridium complex and weak phosphate base to furnish a reactive amidyl radical that readily adds to pendant alkenes. A series of H-a...

Chiral olefin ligands-new "spectators" in asymmetric catalysis.

Proton Transfer in Ribozyme Catalysis

This chapter provides an overview of recent progress in understanding proton transfer in RNA enzymes. It was over 10 years ago that the previous book by the same editors was published. In that volume, there was no chapter on proton transfer. Indeed, it was unclear whether proton transfer made important contributions to RNA catalysis. Many things have changed in the last decade. Most importantly...

Simple, Chemoselective, Catalytic Olefin Isomerization

Catalytic amounts of Co(Sal(tBu,tBu))Cl and organosilane irreversibly isomerize terminal alkenes by one position. The same catalysts effect cycloisomerization of dienes and retrocycloisomerization of strained rings. Strong Lewis bases like amines and imidazoles, and labile functionalities like epoxides, are tolerated.