N-phosphinyl imine chemistry (I): design and synthesis of novel N-phosphinyl imines and their application to asymmetric aza-Henry reaction.
Novel chiral N-phosphinamide and N-phosphinyl imines have been designed, synthesized and applied to asymmetric aza-Henry reaction to give excellent chemical yields (92%- quant.) and diastereoselectivity (91% to >99%de). The reaction showed a great substrate scope in which aromatic/aliphatic aldehyde- and ketone-derived N-phosphinyl imines can be employed as electrophiles. The chiral N-phosphinamide can be stored at room temperature for more than 2 months without inert gas protection, and chiral N-phosphinyl imines were also proven to be highly stable at room temperature for a long period under inert gas protection. The N-phosphinyl group enabled the product purification to be performed simply by washing crude product with EtOAc and hexane. This reaction joined other eight GAP (Group-Assistant-Purification) chemistry processes that were developed in our laboratories. The absolute configuration has been unambiguously determined by converting a β-nitroamine product into a known N-Boc sample.
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061, USA.
Suresh
S
Pindi
Parminder
P
Kaur
Gaurav
G
Shakya
Guigen
G
Li
D000447:Aldehydes / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D007097:Imines / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D017976:Phosphorus Acids / Q000737:chemistry; D013237:Stereoisomerism
D000447:Aldehydes; D000588:Amines; D007097:Imines; D007659:Ketones; D017976:Phosphorus Acids