Synthesis of Enantiopure Planar-Chiral Thiourea Derivatives

Abstract

An efficient access to enantiopure pseudo-geminally substituted 4-amino-13-bromo[2.2]paracyclophane is described. The aminobromide was employed in cross-coupling reactions to yield arylated 4-amino[2.2]paracyclophanes. The amines were converted into enantiopure planar-chiral thioureas, which are potential hydrogen-bond donors for enantioselective organocatalysis.

Key words

thiourea - hydrogen-bond donor - planar-chiral - cross-coupling

References

• 1a Hydrogen Bonding in Organic Synthesis   Pihko PM. Wiley-VCH; Weinheim: 2009. 
• 1b Zhang ZG. Schreiner PR. Chem. Soc. Rev.  2009,  38:  1187 
• 1c Doyle AG. Jacobsen EN. Chem. Rev.  2007,  107:  5713 
• 1d Schreiner PR. Chem. Soc. Rev.  2003,  32:  289 
• 1e Connon SJ. Chem. Eur. J.  2006,  12:  5418 
• 2 Berkessel A. Gröger H. Asymmetric Organocatalysis   Wiley-VCH; Weinheim: 2005. 
• 3 Enantioselective Organocatalysis   Dalko PI. Wiley-VCH; Weinheim: 2007. 
• 4 Ma JA. Cahard D. Angew. Chem. Int. Ed.  2004,  43:  4566 ; Angew. Chem. 2004, 116, 4666
• 5 Schneider JF. Falk FC. Fröhlich R. Paradies J. Eur. J. Org. Chem.  2010,  12:  2265 
• 6a Xin DY. Ma YD. He FY. Tetrahedron: Asymmetry  2010,  21:  333 
• 6b Ma Q. Ma Y. Liu X. Duan W. Qu B. Song C. Tetrahedron: Asymmetry  2010,  21:  292 
• 6c Qu B. Ma YD. Ma QS. Liu X. He FY. Song C. J. Org. Chem.  2009,  74:  6867 
• 6d Duan WZ. Ma YD. Xia HQ. Liu XY. Ma QS. Sun JS. J. Org. Chem.  2008,  73:  4330 
• 7 Kreis M. Friedmann CJ. Bräse S. Chem. Eur. J.  2005,  11:  7387 
• 8a Allgeier H. Siegel MG. Helgeson RC. Schmidt E. Cram DJ. J. Am. Chem. Soc.  1975,  97:  3782 
• 8b Reich HJ. Cram DJ. J. Am. Chem. Soc.  1969,  91:  3505 
• 8c Norcross BE. Becker D. Cukier RI. Schultz RM. J. Org. Chem.  1967,  32:  220 
• 8d Singer LA. Cram DJ. J. Am. Chem. Soc.  1963,  85:  1080 
• 9a Pelter A. Crump RANC. Kidwell H. Tetrahedron: Asymmetry  1997,  8:  3873 
• 9b Lahann J. Hocker H. Langer R. Angew. Chem. Int. Ed.  2001,  40:  726 ; Angew. Chem. 2001, 113, 3034
• 10 Roche AJ. Dolbier WR. J. Org. Chem.  2000,  65:  5282 
• 12a Cristau HJ. Cellier PP. Spindler JF. Taillefer M. Eur. J. Org. Chem.  2004,  695 
• 12b Cristau HJ. Cellier PP. Spindler JF. Taillefer M. Chem. Eur. J.  2004,  10:  5607 
• 14 COLLECT   Nonius B.V.; Delft: 1998. 
• 15 Otwinowski Z. Minor W. In Methods in Enzymology   Vol. 276:  Carter CW. Sweet RM. Academic Press; New York: 1997.  p.307-326  
• 16 Otwinowski Z. Borek D. Majewski W. Minor W. Acta Crystallogr., Sect. A  2003,  59:  228 
• 17 Sheldrick GM. Acta Crystallogr., Sect. A  1990,  46:  467 
• 18 Sheldrick GM. Acta Crystallogr., Sect. A  2008,  64:  112 
• 19 Keller E. SCHAKAL, Molecular Structure Visualization   University of Freiburg; Germany: 1997. 

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Compound 7c was reported by Ma and co-workers; see ref. 6c.

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CCDC 775030 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge at www.ccdc.cam.ac.uk/conts/retrieving.html [or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: [phone], E-mail: [e-mail]].