70823-23-3Relevant academic research and scientific papers
Catalytic asymmetric alkylation reactions for the construction of protected ethylene-amino and propylene-amino motifs attached to quaternary stereocentres
Moss, Thomas A.,Barber, David M.,Kyle, Andrew F.,Dixon, Darren J.
supporting information, p. 3071 - 3081 (2013/03/28)
An efficient catalytic and stereoselective method for the direct construction of protected ethylene-amino and propylene-amino scaffolds attached to quaternary stereocentres is reported. Preliminary investigations revealed a mild base catalysed nucleophilic ring opening of N-sulfonyl aziridines using the commercially available phosphazene base 2-tert-butylimino-2-diethylamino-1,3- dimethyl-perhydro-1,3,2-diazaphosphorine (BEMP) was possible and resulted in highly efficient alkylation reactions with a range of methine carbon acids. This reaction could be rendered highly asymmetric (up to 97 % ee) by employing phase-transfer catalysis to control stereoinduction. Incorporation of alkyl substituents onto the aziridine electrophile, resulted in a highly diastereoselective (up to 30:1 d.r.) variant of this methodology. A further extension using N-protected cyclic sulfamidates as the electrophilic component was successful with a range of pro-nucleophiles (up to 96 % ee and 45:1 d.r.) and allowed a range of nitrogen protecting groups (carbamate, sulfonyl, phosphonyl, benzyl) to be incorporated into the alkylation adducts. Finally, the utility of the products have been demonstrated in the synthesis of useful heterocycles and compounds bearing structural components of natural products. Open sesame: The enantio- and diastereoselective nucleophilic ring opening of protected aziridines and cyclic sulfamidates using asymmetric phase-transfer catalysis (PTC) is reported. The ring-opening alkylation reactions create quaternary chiral centres containing ethylene- and propylene-amino motifs in good yields with good to excellent enantioselectivities (see scheme). These reactions are broad in scope and a wide range of pro-nucleophiles are tolerated. Copyright
Efficient base catalyzed alkylation reactions with aziridine electrophiles
Moss, Thomas A.,Alba, Aurelie,Hepworth, David,Dixon, Darren J.
supporting information; experimental part, p. 2474 - 2476 (2009/02/03)
N-Mesitylene sulfonyl and N-tosyl aziridines have been identified as effective electrophiles in alkylation reactions of carbon acids catalyzed by the organic phosphorine base BEMP; yields of up to 99% for a range of pro-nucleophiles under mild reaction co
