Chiral imidazolium salts for asymmetric catalysis
Planar chiral N-heterocyclic carbenes that incorporate an iron sandwich complex into the NHC framework are disclosed for use in organocatalytic and transition metal-catalyzed reactions.
1. A catalyst compound selected from a group consisting of
2. A method of preparing an addition product of a homoenolate and an α-ketoester comprising contacting the homoenolate and the α-ketoester with a compound of claim 1 and affording an annulation product.
3. A method for nickel-catalyzed reductive coupling of an aldehyde and to an alkyne comprising contacting the aldehyde and the alkyne with a nickel catalyst and a compound of claim 1 and affording an allylic alcohol.
4. A method according to claim 3 , wherein the allylic alcohol is formed in an enantiometeric ratio of about 93:7.
5. A method according to claim 3 , wherein the allylic alcohol is formed with about 20:1 regioselectivity.
6. A method for copper-catalyzed conjugate borylation of an α,β-unsaturated ester comprising complexing a compound of claim 1 with CuCl to form a catalytic complex, contacting the α,β-unsaturated ester and a boron-containing compounds with the catalytic complex, and affording a conjugate product.
7. A method according to claim 6 , wherein the catalytic complex is a complex comprising CuCl and
8. A method according to claim 7 , wherein the boron-containing compound is bis(pinacolato)diboron.