A one-step synthesis of enantiopure 2-substituted 4,5-dihydro-1,4-benzodiazepine-3-ones via intramolecular azide cycloaddition
摘要:
Starting from the appropriate azides bearing the (S)-1-phenylethylamine and the L-alanine benzylester as chiral pendants, a facile and effective synthetic route to the title compounds in their enantiopure form was developed with excellent product yields obtained. Basic hydrolysis of the ester group of the title compounds 3a-c gave the corresponding, readily functionalisable carboxylic acids. Catalytic reduction of 2-benzyl derivatives 3c and 3f gave 4-functionalised 1,2,4,5-tetrahydro-1,4-benzodiazepin-3-ones in enantiopure forms. (C) 2007 Elsevier Ltd. All rights reserved.
Asymmetric induction by the (S)-1-phenylethyl group in intramolecular nitrile imine cycloadditions giving enantiopure 3,3a-dihydro-pyrazolo[1,5-a][1,4]benzodiazepine-4(6H)-ones
摘要:
Stereoselective intramolecular cycloadditions of homochiral nitrile imines 5 are described as a fruitful source of enantiopure 3,3a-dihydro-pyrazolo[1,5-a][1,4]benzodiazepine-4(6H)-ones 6 and 7. (C) 1999 Elsevier Science Ltd. All rights reserved.