Type 2 intramolecular N-acylazo Diels-Alder reaction: regio- and stereoselective synthesis of bridgehead bicyclic 1,2-diazines.
The type 2 intramolecular N-acylazo Diels-Alder reaction provides a regio- and stereoselective synthesis of bicyclic 1,2-diazine systems. A new method for the generation of N-acylazo dienophiles with tetra-n-butylammonium periodate is reported. X-ray crystallographic analysis allowed the quantification of structural distortions of the nonplanar bridgehead olefin and lactam functionalities in 1,2-diazine cycloadducts 11 and 15. Caprolactams and enantholactams were formed by stereoselective bridgehead alkene reduction, a process that transfers stereochemistry from the bridgehead lactam nitrogen to the bridgehead carbon. The sequence of transformations offers a convenient route for the diastereoselective synthesis of medium-ring nitrogen heterocycles and 1,4-diamines.
Department of Chemistry, Natural Science II, University of California Irvine, Irvine, California 92697-2025, USA.
Claudia L
CL
Molina
Chun P
CP
Chow
Kenneth J
KJ
Shea
D000143:Acids / Q000737:chemistry; D000215:Acylation; D001372:Aza Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003432:Cross-Linking Reagents / Q000138:chemical synthesis*; D018360:Crystallography, X-Ray; D003500:Cyclization; D006834:Hydrazines / Q000737:chemistry; D047028:Macrocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D000143:Acids; D001372:Aza Compounds; D003432:Cross-Linking Reagents; D006834:Hydrazines; D047028:Macrocyclic Compounds; C029424:hydrazine; D009584:Nitrogen