Dimethyl sulfide and chlorine

Dimethyl snlfoxide-Oxalyl chloride, 8, 200. Swern and co-workers have suggested that the acutal oxidizing agent from DMSO and oxalyl chloride is 1, formed by almost instantaneous loss of CO2 and CO. This is also the reagent obtained by Corey and Kim from dimethyl sulfide and chlorine. (4, 191). 

OxUatiou of primary and secondary alcohals to carbonyl compounds. Corey and Kim report that the complex of N-chlorosuccinimide and dimethyl sulfide is somewhat superior to the complex of dimethyl sulfide and chlorine (this volume) for oxidation of primary and secondary alcohols the formation of hydrogen chloride is avoided and yields are generally higher. The procedure is illustrated for the oxidation of 4-r-butyl-cyclohexanol (2) to 4-r-butylcyclohexanonc (4). The complex (1) is prepared by addition of dimethyl sulfide (4.1 mmole) to a stirred solution of NCS (3.0 mmole) in toluene at 0° under argon. The mixture is cooled to -25° and a solution of 4-r-butylcyclo-hexanol (2.0 mmole, mixture of cis and trans) in toluene is added dropwise. The stirring is continued for 2 hr. at — 25° and then triethylamine (3.0 mmole) in toluene is added dropwise. The ketone (4) is obtained in almost quantitative yield. As in oxidation with the complex of dimethyl sulfide and chlorine, an intermediate sulfoxonium complex (3) is involved. 

Dimethyl sulfide and chlorine or, better still, dimethyl sulfide and N-chlorosuccinimide, form a system capable of the selective dehydrogenation of alcohols to aldehydes or ketones. The intermediates, such as (013)28 C1 Cr, react with bases according to the scheme in equation 25 [720],... 

Dimethyl sulfide and chlorine or A-chlorosuccinimide (NCS) oxidize primary alcohols to aldehydes in high yields under very mild conditions. 

Thus, Corey and Kim explained in 1972248 that reaction of dimethyl sulfide with chlorine yields chlorodimethylsulfonium chloride, which is precisely the same species described later249 as the activated DMSO species, generated during a Swern oxidation. 

Dimethyl sulfoxide and chlorine form highly reactive intermediates which are of some limited use as oxidants for alcohols. These intermediates are related to those derived from the reaction of the halogens with dimethyl sulfide and probably have a structure such as (27). When formed at -4S C they allow the oxidation of primary and secondary alcdiols to aldehydes and ketones when used in a two-fold excess. For very simple alcdiols the reaction proceeds in yields of greater than 90%, but there are considerable drawbacks if some types of additional functionality are present in the molecule, e.g. alkenes react very rapidly to form vicinal dichlorides. 

An alternative method for the formation of aldehydes or ketones makes use of the complexes formed from a methyl sulfide with chlorine or A-chlorosuccinimide (NCS), in what is called the Corey-Kim oxidation. With dimethyl sulfide the salt 28 is generated and reacts with the alcohol to give the alkoxysulfonium salts and hence, on treatment with a base, the carbonyl compound. This reaction has fovmd particular application in the oxidation of 1,2-diols in which one alcohol is tertiary, to give a-hydroxy-aldehydes or ketones without rupture of the carbon-carbon bond. For example, the aldehyde 32 is formed in good yield from the diol 31 using dimethyl sulfide and NCS followed by addition of triethylamine (6.29). This transformation is thought to depend on the preferential five-membered transition... 

Stelson, A. W and J. H. Seinfeld, Chemical Mass Accounting of Uban Aerosol, Environ. Sci. Technol., 15, 671-679(1981). Stickel, R. E., J. M. Nicovich, S. Wang, Z. Zhao, and P. H. Wine, Kinetic and Mechanistic Study of the Reaction of Atomic Chlorine with Dimethyl Sulfide, J. Phys. Chem., 96, 9875-9883 (1992). Swartz, E J. Boniface, I. Tchertkov, O. V. Rattigan, D. V. Robinson, P. Davidovits, D. R. Worsnop, J. T. Jayne, and C. E. Kolb, Horizontal Bubble Train Apparatus for Heterogeneous Chemistry Studies Uptake of Gas-Phase Formaldehyde, Environ. Sci. Technol, 31, 2634-2641 (1997). 

Langer, S., B. T. McGovney, and B. J. Finlayson-Pitts, The Dimethyl Sulfide Reaction with Atomic Chlorine and Its Implications for the Budget of Methyl Chloride, Geophys. Res. Lett., 23, 1661-1664 (1996). 

Shekel, R. E., J. M. Nicovich, S. Wang, Z. Zhao, and P. H. Wine, Kinetic and Mechanistic Study of the Reaction of Atomic Chlorine with Dimethyl Sulfide, J. Phys. Chem., 96, 9875-9883 (1992). 

Corey and Kim described an oxidation,6a in which activated DMSO is not generated by activation of DMSO, but by oxidation of dimethyl sulfide. Although, they described only the use of chlorine and /V-chlorosuccinimidc as dimethyl sulfide oxidants, we propose that the name Corey-Kim oxidations be applied to alcohol oxidations, in which activated DMSO is generated by oxidation of dimethyl sulfide, regardless of the oxidant employed. 

As operation with gaseous chlorine is dangerous and inconvenient, Corey Kim oxidations are normally performed by oxidation of dimethyl sulfide with /V-chIorosuccinimide rather than with chlorine. This results in the formation of a different kind of active DMSO species, in which a sulfur-nitrogen bond is present. 

Chlorodimethylsulfonium chloride (generated from chlorine and dimethyl sulfide) can be used in the same way for preparation of a-chloro ketones. 

Oxidation of primary and secondary alcohols to carbonyl compounds, Treatment of dimethyl sulfide in carbon tetrachloride at 0° with 1 eq. of chlorine in the same solvent results in rapid formation of the partially insoluble complex (I). This complex has been used by Corey and Kim for oxidation of primary and secondary alcohols. In a typical... 

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