Inter- and Intramolecular Imino Diels-Alder Reactions Catalyzed by Sulfamic Acid: A Mild and Efficient Catalyst for a One-Pot Synthesis of Tetrahydroquinolines

Abstract

The successful use of sulfamic acid as a catalyst in the inter- and intramolecular Inverse Electron Demand Diels-Alder reactions of iminodienes is described. A one-pot synthesis of tetrahydroquinolines was achieved by three component coupling of benzaldehyde and anilines with electron-rich dienophiles such as 2,3-dihydrofuran, dihydropyran and cyclopentadiene catalyzed by sulfamic acid (H₂NSO₃H). The intramolecular cycloaddition of imines, derived from O-prenylsalicylaldehyde with anilines catalyzed by sulfamic acid proceeds smoothly and yielded the diastereomeric tetrahydrochromanoquinolines in good yields.

Key words

sulfamic acid - tetrahydroquinolines - imines - intra­molecular - chromanoquinolines

References

• 1a Weinreb SM. In Comprehensive Organic Synthesis   Vol. 5:  Trost BM. Fleming I. Paquette LA. Pergamon; Oxford: 1991.  p.401 
• 1b Boger DL. Weinreb SM. Hetero Diels-Alder Methodology in Organic Synthesis   Academic; San Diego: 1987.  Chap. 2 and 9.
• 1c Qiang LG. Baine NH. J. Org. Chem.  1988,  53:  4218 
• 2a Povarov LS. Russ. Chem. Rev.  1967,  36:  656 
• 2b Grieco PA. Bahsas A. Tetrahedron Lett.  1988,  29:  5855 
• 2c Mellor JM. Merriman GD. Tetrahedron  1995,  51:  6115 
• 2d Kobayashi S. Nagayama S. J. Am. Chem. Soc.  1996,  118:  8977 
• 2e Crousse B. Begue J.-P. Bonnet-Dolpon D. J. Org. Chem.  2000,  65:  5009 
• 2f Yadav JS. Reddy BVS. Reddy JSS. Rao RS. Tetrahedron  2003,  59:  1599 
• 2g Powell DA. Batey RA. Tetrahedron Lett.  2003,  44:  7569 
• 3a Katritzky AR. Rachwal S. Rachwal B. Tetrahedron  1996,  52:  15031 
• 3b Larock RC. Yang H. Pace P. Tetrahedron Lett.  1998,  39:  1885 
• 3c Padwa A. Brodney MA. Liu B. Satake K. Wu T. J. Org. Chem.  1999,  64:  3595 
• 3d Bunce RA. Herron DM. Johnson LB. Kotturi S. J. Org. Chem.  2001,  66:  2822 
• 3e Zhang W. Jia X. Yang L. Zhao G. Liu Z.-L. Tetrahedron Lett.  2002,  43:  9433 
• 4 Lucchini V. Prato M. Scorrano G. Tecilla P. J. Org. Chem.  1998,  53:  2251 
• 5 Ma Y. Qian C. Xie M. Sun J. J. Org. Chem.  1999,  64:  6462 
• 6 Kobayashi S. Ishitani H. Nagayama S. Synthesis  1995,  1195