A Facile and Efficient Method for the Reduction of Sulfoxides into Sulfides with an Al-NiCl₂·6H₂O System

Abstract

It has been observed that alkyl aryl and dialkyl sulfoxides can be conveniently and rapidly converted to the corresponding sulfides with an Al-NiCl₂·6H₂O system in high yields. Ketones are not affected under these reaction conditions.

Key words

sulfoxides - reduction - sulfides - aluminium - nickel chloride hexahydrate

References

• 1a Block E. J. Chem. Ed.  1971,  48:  814 
• 1b Fleming I. Chem. Ind. (London)  1975,  449 
• 1c Davidson AH. Hodgson PKG. Howells D. Warren S. Chem. Ind. (London)  1975,  455 
• 2 Drabowicz J. Numata T. Oae S. Org. Prep. Proced. Int.  1977,  9:  63 
• 3a Madesclaire M. Tetrahedron  1988,  44:  6537 
• 3b Drabowicz J. Dudzinski B. Mikolajczyk M. Synlett  1992,  252 
• 3c Mohanazadeh F. Momeni AR. Ranjbar Y. Tetrahedron Lett.  1994,  35:  6127 
• 3d Lee GH. Choi EB. Lee E. Pak CS. Tetrahedron Lett.  1994,  35:  2195 
• 3e Zhang Y. Yu Y. Bao W. Synth. Commun.  1995,  25:  1825 
• 3f Wang JQ. Zhang YM. Synth. Commun.  1995,  25:  3545 
• 3g Nicolas E. Vilaseca M. Giralt E. Tetrahedron  1995,  51:  5701 
• 3h Fujiki K. Kurita S. Yoshida E. Synth. Commun.  1996,  19:  3619 
• 3i Wang Y. Koreeda M. Synlett  1996,  885 
• 4 Black S. Harte EM. Hudson B. Wartofsky L. J. Biol. Chem.  1960,  235:  2910 
• 5a Drabowicz J. Numata T. Oae S. Org. Prep. Proced. Int.  1977,  9:  63 
• 5b Iranppoor N. Firouzabadi H. Shaterian HR. J. Org. Chem.  2002,  67:  2826 
• 5c Miller SJ. Collier TR. Wu W. Tetrahedron Lett.  2000,  41:  3781 
• 5d Yoo BW. Choi KH. Lee SJ. Yoon CM. Kim SH. Kim JH. Synth. Commun.  2002,  32:  63 
• 5e Somasundaran N. Srinivasan C. Ind. J. Chem., Sect. B  2002,  41:  1523 
• 5f Yoo B. Choi KH. Kim DY. Choi Kyung . Kim JH. Synth. Commun.  2003,  33:  53 
• 6a Drabowicz J. Togo H. Mikolajczyk M. Oae S. Org. Prep. Proced. Int.  1984,  16:  171 
• 6b Nuzzo RG. Simon HJ. Filippo JS. J. Org. Chem.  1977,  42:  568 
• 6c Chasar DW. J. Org. Chem.  1971,  36:  613 
• 7 Amos RA. J. Org. Chem.  1985,  50:  1311 ; and references cited therein
• 8a Lee GH. Choi EB. Lee E. Pak CS. Tetrahedron Lett.  1994,  35:  2195 
• 8b Hepworth H. Clapham HN. J. Chem. Soc.  1921,  119:  1188 
• 9a Gazder M. Smiles S. J. Chem. Soc.  1910,  97:  2248 
• 9b Kobayashi K. Kubota Y. Furukawa N. Chem. Lett.  2000,  400 
• 10a Dyer JC. Evans SA. J. Org. Chem.  1980,  45:  5350 
• 10b Dilajan HS. Weber WP. Tetrahedron Lett.  1970,  969 
• 11 Johnson CR. Bacon CC. Rigau JJ. J. Org. Chem.  1972,  37:  919 
• 12 Oae S. Kawamura S. Bull. Chem. Soc. Jpn.  1963,  36:  163 
• 13 Nagata T. Yoshimura T. Fujimori K. Oae S. Tetrahedron Lett.  1984,  25:  341 
• 14a Saikia AK. Tsuboi S. J. Org. Chem.  2001,  66:  643 
• 14b Kar G. Saikia AK. Bora U. Dehury SK. Chaudhuri MK. Tetrahedron Lett.  2003,  44:  4503 
• 15a Sarmah BK. Barua NC. Tetrahedron  1991,  47:  8587 
• 15b Bezbarua MS. Bez G. Barua NC. Chem. Lett.  1999,  325 
• 16 Wang WB. Shi LL. Huang YZ. Tetrahedron Lett.  1990,  31:  1185 
• 17 Barua M. Boruah A. Prajapati D. Sandhu JS. Tetrahedron Lett.  1996,  37:  4559 
• 20a Shiota and co-workers prepared precipitated nickel by adding wet NiCl₂·6H₂O and hot zinc powder. See: Ishige M. Shiota M. Can. J. Chem.  1975,  53:  1700 
• 20b

  When added to NiCl₂·6H₂O, aluminum powder reacts vigorously without heating. The reaction must be cooled for the heat to subside.

18

General Procedure:
In a typical procedure, NiCl₂·6H₂O (10 mmol) and aluminum powder (10 mmol) were added to an ice-cooled solution of the substrate (1.0 mmol) in freshly distilled THF. An exothermic reaction took place immediately and stirring was continued for a specified period of time. The reaction mixture was monitored by TLC. After completion of the reaction, the reaction mixture was diluted with EtOAc and filtered. The residue was washed with EtOAc several times, and the combined filtrate and washings were dried (Na₂SO₄) and evaporated to dryness. Finally, the crude product thus obtained was purified by column chromatography using EtOAc and hexane as eluent and characterized by IR, NMR and elemental analysis.¹⁹

19

Ethyl Octadecyl Sulfide: ¹H NMR (300 MHz): δ = 0.88 (t, J = 6.0 Hz, 3 H, -CH₃), 1.35 (m, 33 H, CH₂-, -CH₃), 1.55 (m, 2 H, -CH₂-), 2.53 (m, 4 H, -CH₂SCH₂-). IR: 2925, 2863, 1465, 723 cm^-1. Anal. Calcd for C₂₀H₄₂S: C, 76.35; H, 13.46; S, 10.19. Found: C, 76.52; H, 13.17; S, 10.38.
n -Pentyl-2-hydroxyethyl Sulfide: ¹H NMR (300 MHz): δ = 0.88 (t, J = 6.0 Hz, 3 H, -CH₃), 1.34 (m, 4 H, 2-CH₂-), 1.57 (m, 2 H, -CH₂-), 2.50 (t, J = 7.2 Hz, 2 H, -SCH₂-), 2.70 (t, J = 6.0 Hz, 2 H, -SCH₂-), 3.69 (t, J = 6.0 Hz, 2 H, -CH₂-O-). IR: 3391, 2960, 2935, 2858, 1465, 1050, 1015, 774 cm^-1. Anal. Calcd for C₉H₁₈O₂S: C, 56.80; H, 9.53; S, 16.85. Found: C, 57.12; H, 9.36; S, 17.14.
n -Pentyl Phenyl Sulfide: ¹H NMR (300 MHz): δ = 0.87 (t, J = 7.0 Hz, 3 H, -CH₃), 1.37 (m, 4 H, 2-CH₂-), 1.65 (m, 2 H, -CH₂-), 2.8 (t, J = 7.11 Hz, 2 H, -S-CH₂-), 7.54 (m, 5 H, aromatic). IR: 2930, 2858, 1588, 1486, 1107, 1025, 748
cm^-1. Anal. Calcd for C₁₁H₁₆S: C, 73.27; H, 8.94; S, 17.78. Found: C, 73.43; H, 9.18; S, 17.52.
2-Ethylsulfinyl Ethyl Acetate: ¹H NMR (300 MHz): δ = 1.38 (t, J = 7.38 Hz, 3 H, -CH₃), 2.07 (s, 3 H, CH₃CO-), 2.55 (t, J = 7.50 Hz, 2 H, -CH₂S-), 2.74 (t, J = 7.50 Hz, 2 H,
-CH₂S-), 4.22 (t, J = 6.90 Hz, 2 H, -CH₂-OAc). IR: 2965, 2924, 1741, 1460, 1229, 1034, 748 cm^-1.
Phenysulfinylacetone: ¹H NMR (400 MHz): δ = 2.27 (s, 3 H, -CH₃), 3.66 (s, 2 H, -SOCH₂CO-), 7.21 (m, 2 H, ArH), 7.32 (m, 3 H, ArH). ¹³C NMR (100 MHz): δ = 28.42, 45.06, 127.10, 129.35, 129.70, 134.84, 203.56. IR: 3073, 2935, 1711, 1358, 1235, 1163, 1025, 743 cm^-1.