An Efficient Method for the Synthesis of Symmetrical Disiloxanes from Alkoxysilanes Using Meerwein’s Reagent

Abstract

We report here a new and efficient route to symmetrical disiloxanes from their corresponding alkoxysilanes using Meerwein’s reagent as mediator and potassium carbonate as additive under mild reaction conditions in acetonitrile. Our methodology is very simple, economic, and high yielding. We have also proposed a reaction mechanism with the plausible silyloxonium intermediates.

Key words

Meerwein’s reagent - disiloxane - alkoxysilane condensation - fluorine anion - silicon

• References and Notes

• 1a Perry RJ, Hubbard PA. PCT Int. Appl WO 2002077356, 2002 ; Chem. Abstr. 2002, 137, 281058
• 1b Dershem SM. U.S. Patent Appl. 2010041823, 2010 ; Chem. Abstr. 2010, 152, 263916
• 2 Białecka-Florjańczyk E, Sołtysiak JT. J. Organomet. Chem. 2010; 695: 1911
• 3 Gavillon R, Simonnet J.-T, Aubrun O. PCT Int Appl. 2010070138, 2010 ; Chem. Abstr. 2010, 153, 125361
• 4a Liu T.-K, Hsieh C.-F. U.S. Patent Appl. 20100311922, 2010 ; Chem. Abstr. 2010, 153, 644411
• 4b Kojima K, Naganawa T, Harashima A. PCT Int. Appl. WO 2010074295, 2010 ; Chem. Abstr. 2010, 153, 120126
• 4c Hamachi T, Ozaki M, Tanaka H. PCT Int. Appl. WO 2002088253, 2002 ; Chem. Abstr. 2002, 137, 357888
• 5 Pihan SA, Tsukruk T, Förch R. Surf. Coat. Technol. 2009; 203: 1856
• 6a Corrie TI, Peter AH. Chem. Soc. Rev. 2007; 36: 2096
• 6b Engel M, Hisgen B, Keller R, Kreuder W, Reck B, Ringsdorf H, Schmidt H.-W, Tschirnerp P. Pure Appl. Chem. 1985; 57: 1009
• 7 Kondo S, Fukuda A, Yamamura T, Tanaka R, Unno M. Tetrahedron Lett. 2007; 48: 7946
• 8 Seto I, Gunji T, Kumagai K, Arimitsu K, Abe Y. Bull. Chem. Soc. Jpn. 2003; 76: 1983
• 9 Narumi F, Morohashi N, Matsumura N, Iki N, Kameyama H, Miyano S. Tetrahedron Lett. 2002; 43: 621
• 10 Napier S, Marcuccio SM, Tye H, Whittaker M. Tetrahedron Lett. 2008; 49: 3939
• 11 Pietraszuk C, Rogalski S, Majchrzak M, Marciniec B. J. Organomet. Chem. 2006; 691: 5476
• 12 Ison EA, Corbin RA, Abu-Omar MM. J. Am. Chem. Soc. 2005; 127: 11938
• 13 Matsuo T, Kawaguchi H. J. Am. Chem. Soc. 2006; 128: 12362
• 14 Chojnowski J, Rubinsztajn S, Cella JA, Fortuniak W, Cypryk M, Kurjata J, Kaźmierski K. Organometallics 2005; 24: 6077
• 15 Sridhar M, Ramanaiah BC, Narsaiah C, Swamy MK, Mahesh B, Reddy MK. K. Tetrahedron Lett. 2009; 50: 7166
• 16 Pfeiffer J, Kickelbick G, Schubert U. Organometallics 2000; 19: 957
• 17a Meerwein H, Hinz G, Hofmann P, Kroning E, Pfeil E. J. Prakt. Chem. 1937; 147: 257
• 17b Meerwein H. Org. Synth. 1966; 46: 113
• 17c Granik VG, Pyatin BM, Glushkov RG. Russ. Chem. Rev. 1971; 40: 747
• 18 Jorapur YR, Mizoshita N, Maegawa Y, Nakagawa H, Hasegawa T, Tani T, Inagaki S, Shimada T. Chem. Lett. 2012; 41: 280
• 19a Jorapur YR, Shimada T. Synlett 2012; 23: 1064
• 19b For detailed experimental procedure for the synthesis of fluorosilanes using Meerwein’s reagent, see the Supporting Information
• 20 Maegawa Y, Nagano T, Yabuno T, Nakagawa H, Shimada T. Tetrahedron 2007; 63: 11467
• 21 Typical Experimental Procedure for the Synthesis of Symmetrical Disiloxane (Table 1, entries 2, 8 and 9): A dry and nitrogen-flushed 10-mL screw-capped vial was charged with alkoxysilane (1.0 mmol), MeCN (5.0 mL) followed by the addition of K₂CO₃ (138.2 mg, 1.0 mmol) and Me₃OBF₄ (148 mg, 1.0 mmol) or Et₃OBF₄ (190 mg, 1.0 mmol) or Et₃OPF₆ (248 mg, 1.0 mmol). The reaction mixture was stirred at 100 °C for 90 min and quenched by dropwise addition of H₂O (1.0–2.0 mL). It was then diluted with CH₂Cl₂ and the organic layer was washed with brine, dried over anhyd MgSO₄, and evaporated under reduced pressure. The crude mixture was purified by chromatog-raphy on silica gel (5% EtOAc–hexane as eluent) to give the symmetrical disiloxane. 1,3-Bis(4-bromophenyl)-1,1,3,3-tetra(prop-2-enyl)-disiloxane (2a): colorless liquid. ¹H NMR (270 MHz, CDCl₃): δ = 1.87–1.93 (m, 8 H), 4.86–4.88 (m, 4 H), 4.90–4.94 (m, 4 H), 5.64–5.80 (m, 4 H), 7.37 (d, J = 8.4 Hz, 4 H), 7.49 (d, J = 8.4 Hz, 4 H). ¹³C NMR (68 MHz, CDCl₃): δ = 23.1, 115.3, 124.7, 130.9, 132.6, 134.8, 135.2. HRMS (FAB⁺): m/z [M – C₃H₅]⁺ calcd for C₂₁H₂₃Br₂OSi₂: 504.9654; found: 504.9651. 1,3-Diphenyl-1,1,3,3-tetra(prop-2-enyl)disiloxane (2b): colorless liquid. ¹H NMR (270 MHz, CDCl₃): δ = 1.88–1.92 (m, 8 H), 4.86–4.94 (m, 8 H), 5.69–5.85 (m, 4 H), 7.32–7.40 (m, 6 H), 7.52–7.56 (m, 4 H). ¹³C NMR (68 MHz, CDCl₃): δ = 22.3, 114.8, 127.7, 129.7, 133.2, 133.7, 136.3. HRMS (EI⁺): m/z [M]⁺ calcd for C₂₄H₃₀OSi₂: 390.1835; found: 390.1839. 1,3-Bis(4-methoxyphenyl)-1,1,3,3-tetra(prop-2-enyl)-disiloxane (2c): colorless liquid. ¹H NMR (400 MHz, CDCl₃): δ = 1.85–1.87 (m, 8 H), 3.82 (s, 6 H), 4.86–4.91 (m, 8 H), 5.73–5.80 (m, 4 H), 7.89 (d, J = 6.8 Hz, 4 H), 7.46 (d, J = 6.8 Hz, 4 H). ¹³C NMR (100 MHz, CDCl₃): δ = 23.4, 55.0, 113.4, 114.6, 127.3, 133.4, 135.2, 160.8. HRMS (EI⁺): m/z [M]⁺ calcd for C₂₆H₃₄O₃Si₂: 450.2046; found: 450.2049. 1,3-Bis(4-methylphenyl)-1,1,3,3-tetra(prop-2-enyl)-disiloxane (2d): colorless liquid. ¹H NMR (400 MHz, CDCl₃): δ = 1.86–1.88 (m, 8 H), 2.35 (s, 6 H), 4.86–4.92 (m, 8 H), 5.73–5.80 (m, 4 H), 7.17 (d, J = 7.2 Hz, 4 H), 7.43 (d, J = 7.2 Hz, 4 H). ¹³C NMR (100 MHz, CDCl₃): δ = 21.5, 23.4, 114.6, 128.5, 132.7, 133.4, 133.7, 139.5. HRMS (EI⁺): m/z [M]⁺ calcd for C₂₆H₃₄OSi₂: 418.2148; found: 418.2152

The role of MeCN is currently unclear. For the reports on the formation of N-methyl- and N-ethylnitrilium ions with MeCN in the presence of MR, see:
• 22a Meerwein H, Laasch P, Mersch R, Spille J. Chem. Ber. 1956; 89: 209
• 22b Gordon J, Turrell G. J. Org. Chem. 1959; 24: 269
• 23 Bourget L, Mutin PH, Vioux A, Frances JM. J. Polym. Sci., Part A: Polym. Chem. 1998; 36: 2415
• 24 Kira M, Hino T, Sakurai H. J. Am. Chem. Soc. 1992; 114: 6697
• 25a Olah GA, Li X.-Y, Wang Q, Rasul G, Prakash GK. S. J. Am. Chem. Soc. 1995; 117: 8962
• 25b Olah GA, Doggweiler H, Felberg JD, Frohlich S. J. Org. Chem. 1985; 50: 4847
• 26 Charpentier PA, Li X, Sui R. Langmuir 2009; 25: 3748
• 27 For detailed procedures, see the Supporting Information