Synlett 2004(9): 1565-1568  
DOI: 10.1055/s-2004-829069
LETTER
© Georg Thieme Verlag Stuttgart · New York

Unusual Regio- and Enantioselective [1,2]-Stevens Rearrangement of a Spirobi[dibenzazepinium] Cation

Laurent Viala, Maria-Héléna Gonçalvesa, Pierre-Yves Morgantinib, Jacques Weberb, Gérald Bernardinellic, Jérôme Lacour*a
a Département de Chimie Organique, Université de Genève, Quai Ernest Ansermet 30, 1211 Genève-4, Switzerland
Fax: +41(22)3793215; e-Mail: Jerome.Lacour@chiorg.unige.ch.;
b Département de Chimie Physique, Université de Genève, Quai Ernest Ansermet 30, 1211 Genève-4, Switzerland
c Laboratoire de Cristallographie, Université de Genève, Quai Ernest Ansermet 24, 1211 Genève-4, Switzerland
Further Information

Publication History

Received 26 April 2004
Publication Date:
01 July 2004 (online)

Abstract

Highly symmetric spirobi[dibenzazepinium] cation 3 reacts with P4-t-Bu to form exclusively a ring-expanded tertiary amine; this unusual reactivity can be traced back to the geometry of the ylide.

10

Bis(tetrachlorobenzenediolato) mono([1,1′]binaphthalenyl-2,2′-diolato)phosphate(V) anion: Lacour J., Londez A., Goujon-Ginglinger C., Buß V., Bernardinelli G.; Org. Lett.; 2000, 2: 4185

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Physical data for 4. Rf = 0.94 (basic Al2O3, Et2O). 1H NMR (500 MHz, CDCl3, 233K): δ = 2.98 (dd, J = 13.56 Hz, J = 8.98 Hz,1 H), 3.24 (d, J = 8.98 Hz, 1 H), 3.34 (d, J = 13.56 Hz, 1 H), 3.49 (d, J = 13.71 Hz, 1 H), 3.91 (q AB , ΔνAB = 41.45 Hz, J AB = 14.19 Hz, 2 H), 4.07 (d, J = 13.71 Hz, 1 H), 7.09 (d, J = 7.41 Hz, 1 H), 7.27-7.55 (m, 3 H), 7.65 (d, J = 7.56 Hz, 1 H), 7.67 (d, J = 7.72 Hz, 1 H). 13C NMR (126 MHz, CDCl3, 233K): δ = 38.1, 59.6, 62.3, 62.8, 126.3, 126.4, 126.9, 127.3, 127.4, 127.6, 127.7, 128.0, 128.0, 128.1, 128.5, 128.9, 129.1, 130.1, 130.7, 133.5, 138.7, 139.1, 139.5, 139.9, 140.1, 140.8, 141.0. IR (neat): 3061 (w), 3018 (w), 2923 (m), 2853 (m), 1481 (w), 1441 (m), 1361 (w), 1260 (w), 1191 (w), 1008 (w), 1081 (m), 941 (w), 801 (m), 746 (s) cm-1. HRMS (EI): m/e calcd for C22H19N: 297.15175; found: 297.15084. The ee was measured using CSP-HPLC (Chiracel AD-H, 95/5 i-PrOH-n-hexane, 0.5 mL/min, 23 °C).

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Crystal data for (C28H24N)+Cl-(CHCl3)0.7: M = 493.5, monoclinic, P21/c, a = 16.4658 (14), b = 14.7628 (9), c = 10.7661 (8), β = 101.132 (10)º Å, U = 2567.8 (3) Å3, T = 200 K, Z = 4, µ(MoKα) = 0.384 mm-1. The final R(F) = 0.046, wR(F) = 0.043 and S = 1.00(1). The CHCl3 molecules are disordered on two distinct sites refined for global population parameters of 0.7 and are located on channels parallel to the [001] direction. CCDC 234418.

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The deuterium atom is distributed evenly between the axial and equatorial positions due to the rapid interconversion of the atropisomers of 3.

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Gaussian 98 (Revision A.7): Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Zakrzewski, V. G.; Montgomery, J. A.; Stratmann, R. E.; Burant, J. C.; Dapprich, S.; Millam, J. M.; Daniels, A. D.; Kudin, K. N.; Strain, M. C.; Farkas, O.; Tomasi, J.; Barone, V.; Cossi, M.; Cammi, R.; Mennucci, B.; Pomelli, C.; Adamo, C.; Clifford, S.; Ochterski, J.; Petersson, G. A.; Ayala, P. Y.; Cui, Q.; Morokuma, K.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Cioslowski, J.; Ortiz, J. V.; Baboul, A. G.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Gomperts, R.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Gonzalez, C.; Challacombe, M.; Gill, P. M. W.; Johnson, B. G.; Chen, W.; Wong, M. W.; Andres, J. L.; Head-Gordon, M.; Replogle, E. S.; Pople, J. A. Gaussian, Inc., Pittsburgh PA, 1998.

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With salt [3][Δ-TRISPHAT], no enantioselectivity was expected as no stereoselective induction happens upon ion pairing.12