Abstract
Following the development of a bifunctional benzimidazole containing quinidine
catalyst by Zhang, which gave good yields and ee’s for asymmetric 1,4-addition of
mallonic esters to nitroolefins, a similar reaction path towards a novel bifunctional
benzimidazolederivative containing quinidine catalyst was tested. The structural
difference to that of the Zhang catalyst is that the aminobenzimidazole moiety is on 6’
position of the quinidine backbone instead of the 9 position.
Following the same procedure as Zhang to synthesize the target compound, LC-MS
analysis showed product formation, but with poor conversion. Purification was
troubling because of the many byproducts formed. Decomposition of starting material
and product was observed due to the rough conditions. The target compound was
not isolated as a pure compound.
A novel thiophosphoric triamide was synthesized and tested on catalytic activity
towards 1,4-addition of benzylmercaptane towards a α,β-unsatured carbonyl, but no
conversion was observed for this addition.
New routes have to be explored towards the synthesis of the bifunctional target
compound. More research needs to be done on thiophosphoric triamide catalysts,
because of the potential superior catalytic activity over established thiourea catalysts.