Diethyl Methylsulfinylmethylphosphonate

[50746-61-7]  · C6H15O4PS  · Diethyl Methylsulfinylmethylphosphonate  · (MW 214.22)

(used for the preparation of vinyl sulfoxides and O,S-acetals of formyl phosphonates)

Physical Data: n20D = 1.4766;1 disproportionates before boiling.

Solubility: sol acetone, CH2Cl2, MeOH, THF.

Preparative Methods: diethyl methylsulfinylmethylphosphonate can be obtained by controlled oxidation of Diethyl Methylthiomethylphosphonate, as shown in eq 1.1-4 The procedure using Br2/aq. NaHCO3/CH2Cl2 is notable because use of H218O allows for the preparation of 18O sulfoxides.2

Handling, Storage, and Precautions: Diethyl methylsulfinylmethylphosphonate is reasonably stable for storage. Reactions involving this reagent are best conducted under anhydrous conditions, under nitrogen, in a well ventilated fume hood.


The sulfinylmethylphosphonate can be metalated with n-Butyllithium in THF and then reacted with a variety of aldehydes and ketones to form vinyl sulfoxides via the Horner-Emmons reaction (eq 2).5 Alternatively, the reaction can be conducted under phase transfer conditions, and is then specific for aromatic aldehydes.6 Initially a tetraalkylammonium salt was used as catalyst, but it was discovered that the phosphonate could function as its own phase transfer catalyst.7 Subsequent reports showed that it can function generally as a phase transfer catalyst, for example in the alkylation of benzyl methyl ketone with butyl bromide.8

Diethyl methylsulfinylmethylphosphonate undergoes the Pummerer reaction, resulting in oxidation of the a-carbon with concomitant reduction of the sulfoxide to a sulfide (eq 3).9-12 Limited success in the transfer of chirality from sulfur to carbon has been achieved.11

If the Pummerer reaction is conducted in an aromatic solvent, Freidel-Craft products are produced (eq 4).12,13 In a similar manner, treatment of Pummerer products with alkenes gives ene style products (eq 5).14

1. Mikolajczyk, M.; Zatorski, A. S 1973, 669.
2. Drabowicz, J.; Midura, W.; Mikolajczyk, M. S 1979, 39.
3. Drabowicz, J.; Mikolajczyk, M. S 1978, 758.
4. Drabowicz, J.; Lyzwa, P.; Popielarczyk, M.; Mikolajczyk, M. S 1990, 937.
5. Mikolajczyk, M.; Grzejszczak, S.; Zatorski, A. JOC 1975, 40, 1979.
6. Mikolajczyk, M.; Grzejszczak, S.; Midura, W.; Zatorski, A. S 1975, 278.
7. Mikolajczyk, M.; Grzejszczak, S.; Midura, W.; Zatorski, A. S 1976, 396.
8. Mikolajczyk, M.; Grzejszczak, S.; Zatorski, A.; Montanari, F.; Cinquini, M. TL 1975, 3757.
9. Mikolajczyk, M.; Costisella, B.; Grzejszczak, S.; Zatorski, A. TL 1976, 477.
10. Dinizo, S. E.; Watt, D. S. S 1977, 181.
11. Mikolajczyk, M.; Zatorski, A.; Grzejszczak, S.; Costisella, B.; Midura, W. JOC 1978, 43, 2518.
12. Stamos, I. K. TL 1986, 27, 6261.
13. Kim, T. H.; Kim, D. Y.; Oh, D. Y. SC 1987, 17, 755.
14. Ishibashi, H.; Sato, T.; Irie, M.; Ito, M.; Ikeda, M. JCS(P1) 1987, 1095.

K. Shankaran & Sherman T. Waddell

Merck Research Laboratories, Rahway, NJ, USA

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