862902-30-5

Upstream product

• 53912-80-4 (S)-N-benzylprolinol 
• 100-46-9 benzylamine 
• 147-85-3 L-proline 
• 100-44-7 benzyl chloride 
• 31795-93-4 N-benzyl-L-proline 

Relevant academic research and scientific papers

METHOD FOR PREPARATION OF AMIDES FROM ALCOHOLS AND AMINES BY EXTRUSION OF HYDROGEN

The present invention relates to a method for preparation of carboxamides using alcohols and amines as starting materials in a dehydrogenative coupling reaction catalyzed by a ruthenium N-heterocyciic carbene (NHC) complex, which may be prepared in situ.

Amide synthesis from alcohols and amines catalyzed by ruthenium N-Heterocyclic carbene complexes

The direct synthesis of amides from alcohols and amines is described with the simultaneous liberation of dihydrogen. The reaction does not require any stoichiometric additives or hydrogen acceptors and is catalyzed by ruthenium N-heterocyclic carbene complexes. Three different catalyst systems are presented that all employ 1,3-diisopropylimidazol-2-ylidene (IiPr) as the carbene ligand. In addition, potassium iert-butoxide and a tricycloalkylphosphine are required for the amidation to proceed. In the first system, the active catalyst is generated in situ from [RuCl2(cod)] (cod = 1,5-cyclooctadiene), 1,3-diisopropylimidazolium chloride, tricyclopentylphosphonium tetrafluoroborate, and base. The second system uses the complex [RuCl 2(IiPr)(p-cymene)] together with tricyclohexylphosphine and base, whereas the third system employs the Hoveyda-Grubbs lst-generation metathesis catalyst together with 1,3-diisopropylimidazolium chloride and base. A range of different primary alcohols and amines have been coupled in the presence of the three catalyst systems to afford the corresponding amides in moderate to excellent yields. The best results are obtained with sterically unhindered alcohols and amines. The three catalyst systems do not show any significant differences in reactivity, which indicates that the same catalytically active species is operating. The reaction is believed to proceed by initial dehydrogenation of the primary alcohol to the aldehyde that stays coordinated to ruthenium and is not released into the reaction mixture. Addition of the amine forms the hemiaminal that undergoes dehydrogenation to the amide. A catalytic cycle is proposed with the {(I(Pr)RuII} species as the catalytically active components.

Proline-based N-oxides as readily available and modular chiral catalysts. Enantioselective reactions of allyltrichlorosilane with aldehydes

(Chemical Equation Presented) A proline-based N-oxide is identified that serves as an effective catalyst for the reaction of allyltrichlorosilane with aryl and α,β-unsaturated aldehydes at room temperature to afford the desired homoallylic alcohols in up to 92% ee. The chiral catalyst can be easily prepared from optically pure proline in three simple steps and 60% overall yield.