title: Enantioselective Synthesis of N-PMP-1,2-dihydropyridines via Formal [4 + 2] Cycloaddition between Aqueous Glutaraldehyde and Imines.
abstract: A simple and highly practical one-pot formal [4 + 2] cycloaddition approach for the enantioselective synthesis of N-PMP-1,2-dihydropyridines (DHPs) is described. This chemistry involves an amino-catalytic direct Mannich reaction/cyclization followed by IBX-mediated chemo- and regioselective oxidation sequence between readily available aqueous glutaraldehyde and imines under very mild conditions. A series of N-PMP-1,2-DHPs have been prepared in high yields and excellent enantioselectivity. This method also gives access to both enantiomers of 1,2-DHPs in surplus amount by shifting the catalyst configuration.
authors.affiliation: Department of Chemistry, Birla Institute of Technology and Science , Pilani 333 031, Rajasthan India.
authors.forename: Panduga
authors.initials: P
authors.lastname: Ramaraju
authors.affiliation: Department of Chemistry, Birla Institute of Technology and Science , Pilani 333 031, Rajasthan India.
authors.forename: Nisar A
authors.initials: NA
authors.lastname: Mir
authors.affiliation: Instrumentation Division, IIIM-CSIR Laboratory , Jammu 180 001, Jammu and Kashmir, India.
authors.forename: Deepika
authors.initials: D
authors.lastname: Singh
authors.affiliation: X-ray Crystallography Laboratory, Post-Graduate Department of Physics & Electronics, University of Jammu , Jammu 180 006, Jammu and Kashmir, India.
authors.forename: Vivek K
authors.initials: VK
authors.lastname: Gupta
authors.affiliation: X-ray Crystallography Laboratory, Post-Graduate Department of Physics & Electronics, University of Jammu , Jammu 180 006, Jammu and Kashmir, India.
authors.forename: Rajni
authors.initials: R
authors.lastname: Kant
authors.affiliation: Department of Chemistry, Birla Institute of Technology and Science , Pilani 333 031, Rajasthan India.
authors.forename: Indresh
authors.initials: I
authors.lastname: Kumar
mesh_terms: D002384:Catalysis; D003500:Cyclization; D061565:Cycloaddition Reaction; D004095:Dihydropyridines / Q000737:chemistry*; D005976:Glutaral / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013237:Stereoisomerism
chemical_list: D004095:Dihydropyridines; D007097:Imines; D005976:Glutaral