A Highly Diastereoselective Access to Silicon-Containing Oxazines via the TMSOTf-Promoted Reactions of N-Benzoyl-N,O-acetals with Allyl Silanes

Abstract

A TMSOTf-promoted cycloaddition of N-benzoyl-N,O-acetals with allyl silanes to synthesize silicon-containing oxazines with high diastereoselectivities has been developed. The obtained products might be useful as building blocks in organic synthesis.

Key words

N-benzoyl-N,O-acetals - oxazine - cycloaddition - dia­stereoselectivity

Reference and Notes

• For reviews concerning C-C bond formation using imines as material, see:
• 1a Yamamoto Y. Asao N. Chem. Rev.  1993,  93:  2207 
• 1b Enders D. Reinhold U. Tetrahedron: Asymmetry  1997,  8:  1895 
• 1c Bloch R. Chem. Rev.  1998,  98:  1407 
• 1d Kobayashi S. Ishitani H. Chem. Rev.  1999,  99:  1069 
• 1e Liu M. Sibi MP. Tetrahedron  2002,  58:  7991 
• 1f Friestad GF. Mathies AK. Tetrahedron  2007,  63:  2541 
• 1g Nugent TC. El-Shazly M. Adv. Synth. Catal.  2010,  352:  753 
• For reference on Povarov reaction, see:
• 2a Povarov L. Russ Chem. Rev.  1967,  36:  656 
• 2b Bello D. Ramon R. Lavilla R. Curr. Org. Chem.  2010,  14:  332 
• 2c Glushkov VA. Tolstikov AG. Russ. Chem. Rev.  2008,  77:  137 
• 2d Wang S. Zhao YL. Zhang W. Liu Q. J. Org. Chem.  2007,  72:  4985 
• 2e Akiyama T. Morita H. Fuchibe K.
  J. Am. Chem. Soc.  2006,  128:  13070 
• 2f Twin H. Batey RA. Org. Lett.  2004,  6:  4913 
• 3a Yadav JS. Reddy BVS. Madhuri C. Sabitha G. Jagannadh B. Kumar SK. Kunwar AC. Tetrahedron Lett.  2001,  42:  6381 
• 3b Anniyappan M. Muralidharan D. Perumal Paramasivan T. Tetrahedron  2002,  58:  10301 
• 3c Wang J. Xu F.-X. Lin X.-F. Wang Y.-G. Tetrahedron Lett.  2008,  49:  5208 
• 3d Rueping M. Lin M.-Y. Chem. Eur. J.  2010,  16:  4169 
• 4 Jiménez O. de la Rosa G. Lavilla R. Angew. Chem. Int. Ed.  2005,  44:  6521 
• 5 Ghosh AK. Xu C.-X. Kulkarni SS. Wink D. Org. Lett.  2005,  7:  7 
• 6a Li G. Kaplan MJ. Wojtas L. Antilla JC. Org. Lett.  2010,  12:  1960 
• 6b Cakir SP. Mead KT. Synthesis  2008,  871 
• 7a Momiyama N. Nishimoto H. Terada M. Org. Lett.  2011,  13:  2126 
• 7b Friestad GK. Korapala CS. Ding H. J. Org. Chem.  2006,  71:  281 
• 7c Kiyohara H. Nakamura Y. Matsubara R. Kobayashi S. Angew. Chem. Int. Ed.  2006,  45:  1615 
• 7d Ollevier T. Ba T. Tetrahedron Lett.  2003,  45:  9003 
• 7e Brown RCD. Fisher ML. Brown LJ. Org. Biomol. Chem.  2003,  1:  2699 
• 7f Friestad GK. Ding H. Angew. Chem. Int. Ed.  2001,  40:  4491 
• 7g Uyehara T. Yuuki M. Masaki H. Matsumoto M. Ueno M. Sato T. Chem. Lett.  1995,  24:  789 
• 8a Bates RW. Lu Y. Cai MP. Tetrahedron  2009,  65:  7852 
• 8b Terada M. Machioka K. Sorimachi K. Angew. Chem. Int. Ed.  2009,  48:  2553 
• 8c Liu R.-C. Huang W. Ma JY. Wei B.-G. Lin G.-Q. Tetrahedron Lett.  2009,  50:  4046 
• 8d Myers EL. Vries JG. Aggarwal VK. Angew. Chem. Int. Ed.  2007,  46:  1893 
• 8e Gizecki P. Ait Youcef R. Poulard C. Dhal R. Dujardin G. Tetrahedron Lett.  2004,  45:  9589 
• 8f Gizecki P. Dhal R. Poulard C. Gosselin P. Dujardin G. J. Org. Chem.  2003,  68:  4338 
• 8g Chao W. Weinreb SM. Tetrahedron Lett.  2000,  41:  9199 
• Recent examples concerning the synthetic application of oxazines, see:
• 9a Mulzer M. Coates GW. Org. Lett.  2011,  13:  1426 
• 9b Lee YM. Baek DJ. Lee S. Kim D. Kim S. J. Org. Chem.  2011,  76:  408 
• 9c Liu Z. Byun H.-S. Bittman R. Org. Lett.  2010,  12:  2974 
• 9d Pham V.-T. Joo J.-E. Lee K.-Y. Kim T.-W. Mu Y. Ham W.-H. Tetrahedron  2010,  66:  2123 
• 10 Compared to their carbon analogues, organosilicon compounds exhibit enhanced lipophilicity, stronger OH affinity, and more electropositive character: Bains W. Tacke R. Curr. Opin. Drug Discovery Dev.  2003,  6:  526 
• 11 For details on the stereochemistry assignment of 4,6-disubstituted 1,3-oxzines, see: Katritzky AR. Ghiviriga I. Chen K. Tymoshenko DO. Abdel-Fattah AAA.
  J. Chem. Soc., Perkin Trans. 2  2001,  530 

12

Typical Procedure for the Preparation of Oxazines (13b)
To a mixture of 11a (1 mmol), tert-butyl trimethyl allyl silane (1 mmol) and CH₂Cl₂ (10 mL) was added TMSOTf (0.16 mL, 1 mmol) dropwise at -78 ˚C. After stirring at the same temperature for 1 h, the reaction was quenched by the addition of sat. NaHCO₃ solution (10 mL). The resulting mixture was extracted with CH₂Cl₂ (3 × 10 mL). The combined organic extracts were washed with brine, dried over Na₂SO₄. Removal of the solvent provided the residue which was purified by flash chromatography to afford trans-13b (244 mg, 67%) and cis-13b (40.7 mg, 11%) as colorless oils.
trans-13b: ^¹H NMR (400 MHZ, CDCl₃): δ = 7.94 (d, J = 8.0 Hz, 2 H), 7.34-7.13 (m, 8 H), 4.63 (dd, J = 11.6, 4.8 Hz, 1 H), 4.47-4.40 (m, 1 H), 2.23-2.18 (m, 1 H), 1.47 (dd, J = 24.4, 11.6 Hz, 1 H), 1.05 (dd, J = 14.8, 8.0 Hz, 1 H), 0.87 (dd, J = 14.8, 6.0 Hz, 1 H), 0.81 (s, 9 H), 0.05 (s, 3 H), 0.00 (s, 3 H). ^¹³C NMR (100 MHz, CDCl₃): δ = 156.4, 144.7, 134.2, 130.4, 128.4, 128.0, 127.4, 126.7, 126.4, 74.2, 57.1, 40.6, 26.4, 20.3, 16.5, -4.8, -5.3. ESI-MS: m/z = 366 [M + 1]. Anal. Calcd for C₂₃H₃₁NOSi: C, 75.56; H, 8.55; N, 3.83. Found: C, 75.47; H, 8.37, N, 3.95.
cis-13b: ^¹H NMR (400 MHz, CDCl₃): δ = 8.02 (d, J = 8.0 Hz, 2 H), 7.41-7.20 (m, 8 H), 4.88 (t, J = 4.8 Hz, 1 H), 4.29-4.23 (m, 1 H), 2.06-1.95 (m, 2 H), 1.17 (dd, J = 14.4, 8.0 Hz, 1 H), 0.89 (dd, J = 14.8, 6.8 Hz, 1 H), 0.82 (s, 9 H), 0.00 (s, 3 H), -0.05 (s, 3 H). ^¹³C NMR (100 MHz, CDCl₃): δ = 156.5, 144.5, 134.2, 130.4, 128.3, 128.0, 127.3, 126.8, 126.6, 70.2, 54.3, 37.6, 26.3, 19.8, 16.5, -5.1, -5.3. HRMS: m/z calcd for C₂₃H₃₂NOSi [M + H]⁺: 366.2253; found: 366.2263.