Deportonation of nitroalkanes by bicyclic amidine and guanidine bases; evidence for molecular recognition within a catalytic cycle for C–C bond formation

Evidence from 1H NMR spectroscopy supported by X-ray crystallography, suggests that the bicyclic amidine and guanidine bases 2 and 3 react with nitroalkanes in non-polar organic solvents to give tightly-bound ion pairs 5; it is argued that homochiral analogues of these complexes may prove valuable as intermediates in enantioselective catalytic C–C bond-forming reactions.