Modified Julia-Kocienski Reaction Promoted by Means of m-NPT (Nitro­phenyltetrazole) Sulfone

Abstract

m-Nitrophenyltetrazole sulfone (2) was employed in the Julia-Kocienski reaction. The olefination reaction between 2 and carbonyl compounds proceeded smoothly under Masamune-Roush conditions (DBU and LiCl). These conditions were also applicable to our catechin derivative synthesis. Furthermore, phenolic mesylate was also tolerated in this mild reaction.

Key words

olefination - Julia-Kocienski reaction - sulfone

References and Notes

• 1 Aïssa C. Eur. J. Org. Chem.  2009,  12:  1831 
• 2 Blanchette MA. Choy W. Davis JT. Essenfeld AP. Masamune S. Roush WR. Sakai T. Tetrahedron Lett.  1984,  25:  2183 
• 3 Blakemore PR. Cole WJ. Kocienski PJ. Morley A. Synlett  1998,  26 
• 4 Kan T. Fukuyama T. Chem. Commun.  2004,  353 
• 5 For the use of nitro-substituted aromatic rings for selenation, see: Grieco PA. Gilman S. Nishizawa M. J. Org. Chem.  1976,  41:  1485 
• 6 For azidation, see: Mizuno M. Shioiri T. Chem. Commun.  1997,  2165 
• For macrolactonization, see:
• 7a Shiina I. Ibuka R. Kubota M. Chem. Lett.  2002,  286 
• 7b Shiina I. Chem. Rev.  2007,  107:  239 
• 8 Aïssa C. J. Org. Chem.  2006,  71:  360 
• 10 Hirooka Y. Nitta M. Furuta T. Kan T. Synlett  2008,  3234 
• 13a Kita Y. Toma T. Kan T. Fukuyama T. Org. Lett.  2008,  10:  3251 
• 13b For a similar deprotection of the Ms group by LDA, see: Ritter T. Stanek K. Larrosa I. Carreira EM. Org. Lett.  2004,  6:  1513 

9

Upon treatment of similar p-NPT sulfone derivative 20, under basic conditions, the self-condensation reaction proceeded through Meisenheimer complex 21 to provide 22, as shown in Scheme  [7] .

Scheme 7 Decomposition of 20 under basic conditions

11

Synthesis of sulfone 14: To a stirred solution of iodide 13 (26 mg, 70 µmol) and m-NPTSH 6 (25 mg, 110 µmol) in DMF (1.0 mL), was added K₂CO₃ (15 mg, 110 µmol) at room temperature. After stirring for 90 min, the reaction mixture was quenched with sat. aq NH₄Cl and extracted with CH₂Cl₂. The organic layer was washed with sat. aq NH₄Cl and brine, dried over MgSO₄, and concentrated in vacuo. The residue (28 mg) dissolved in CH₂Cl₂ (1.0 mL) was treated with m-CPBA (42 mg, 244 mmol) and, after stirring at 40 ˚C for 10 h, the reaction mixture was quenched with sat. aq Na₂SO₃ and extracted with CH₂Cl₂. The organic layer was washed with sat. aq Na₂SO₃ and sat. aq NaHCO₃ and brine, dried over MgSO₄, and concentrated in vacuo. The residue was purified by preparative TLC to yield sulfone 14 (21 mg, 43 mmol, 62%, 2 steps). Spectral data for 14: IR (neat): 837, 1101, 1157, 1352, 1539, 2929 cm^-¹; ^¹H NMR (500 MHz, CDCl₃): δ = 0.28 (s, 6 H), 1.01 (s, 9 H), 3.27 (t, J = 8.2 Hz, 2 H), 4.07 (t, J = 8.2 Hz, 2 H), 6.83 (d, J = 8.0 Hz, 1 H), 6.91 (t, J = 8.0 Hz, 1 H), 7.18 (t, J = 8.0 Hz, 1 H), 7.20 (d, J = 8.0 Hz, 1 H), 7.84 (t, J = 8.5 Hz, 1 H), 8,09 (dt, J = 8.5, 1.0 Hz, 1 H), 8.51 (dt, J = 8.5, 1.0 Hz, 1 H), 8.61 (t, J = 1.0 Hz, 1 H); ^¹³C NMR (125 MHz, CDCl₃): δ = -4.0, 18.3, 24.4, 25.9, 55.7, 118.7, 120.8, 121.5, 126.2, 126.4, 128.9, 130.8, 130.9, 131.0, 133.9, 148.7, 153.7, 154.0; FAB-MS: m/z = 490 [M + H]⁺; HRMS: m/z [M + H]⁺ calcd for C₂₁H₂₈O₅N₅SSi: 490.1580; found: 490.1595.

12

Synthesis of 16: To a stirred solution of sulfone 14 (11 mg, 22 µmol), aldehyde 15 (13 mg, 26 µmol) and LiCl (4.0 mg, 78 µmol) in MeCN (1.0 mL) at 0 ˚C, DBU (12 µL, 78 µmol) was added dropwise. After stirring for 20 min, the reaction mixture was quenched with sat. aq NH₄Cl and extracted with CH₂Cl₂. The organic layer was washed with sat. aq NH₄Cl and brine, dried over MgSO₄, and concentrated in vacuo. The residue was purified by preparative TLC to yield 16
(11 mg, 18 µmol, 81%). Spectral data for 16: IR (neat): 839, 1116, 1573, 1693, 2927 cm^-¹; ^¹H NMR (500 MHz, CDCl₃): δ = 0.25 (s, 6 H), 1.02 (s, 9 H), 3.50 (d, J = 7.3 Hz, 2 H), 5,04 (s, 2 H), 5.08 (s, 4 H), 6.25-6.27 (m, 2 H), 6.65 (d, J = 11.6 Hz, 1 H), 6.82 (s, 2 H), 6.91 (d, J = 8.5 Hz, 1 H), 7.10-7.43 (m, 17 H); ^¹³C NMR (68 MHz, CDCl₃): δ = -4.1, 18.3, 25.8, 33.6, 71.1, 71.2, 75.3, 105.9, 118.4, 121.1, 127.2, 127.3, 127.4, 127.7, 127.8, 128.1, 128.4, 128.5, 128.6, 130.3, 130.5, 130.7, 133.5, 137.2, 137.8, 137.9, 152.9, 153.4; FAB-MS: m/z = 642 [M]⁺; HRMS: m/z [M]⁺ calcd for C₄₂H₄₆O₄Si: 642.3165; found: 642.3162.