Chloromethyl p-tolyl sulfone

Bordwell and Cooper211 drew attention to the inertness of a-halosulfones and related compounds towards nucleophilic displacements of the halogen. Thus chloromethyl p-tolyl sulfone reacts with potassium iodide in acetone at less than one-fiftieth of the rate for n-butyl chloride. On the other hand, l-(p-toluenesulfonyl)-3-chloro-l-propene reacts about 14 times faster than allyl chloride. This contrast (and other comparisons) led the authors to attribute the inertness of a-halosulfones to steric hindrance, which was eliminated when the sulfonyl group was more remote from the reaction center. 

Chloromethyl p-tolyl sulfone, ClCH2S02C6H4CH,-p (1). The sulfone is prepared by reaction of CH3C6H4S02Na and BrCH2Cl in DMSO. 

Enantioselective Darzens Reaction. An enantioselective Darzens reaction between ethyl methyl ketone and chloromethyl p-tolyl sulfone in the presence of a chiral ammonium salt derived from (1) and chloromethylpolystyrene affords an optically active a,p-epoxy sulfone in 23% ee. ... 

Various pyridazines, their 3-oxo or 3,6-dioxo analogs, readily undergo vicarious nucleophilic substitution (VNS) with the carbanion of chloromethyl p-tolyl sulfone. 2-Phenyl-3(2//)-pyridazinone, of a higher reactivity as an... 

Chloromethyl p-tolyl sulfone, 340 Chloromethyltrimethylsilane, 307 Chloromethyltrimethyltin, 308 Chloromethyltriphenylphosphonium iodide. 96-97... 

Carbon acids such as chloroacetonitrile and chloromethyl p-tolyl sulfone are readily deprotonated by concentrated aqueous sodium hydroxide under phase transfer conditions. In the presence of aldehydes or ketones, the carbanion undergoes condensation to yield an intermediate a-alkoxy chloride. Intramolecular nucleophilic displacement of halide yields either a glycidic nitrile or a, j3-epoxysulfone. The overall process is, in fact, a phase transfer variant of the Darzens condensation [13] (see Eq. 5.9). Either benzyltriethylammonium chloride (BTEAC) or dibenzo-18-crown-6 (DB-18-C-6) catalyzes the phase transfer Darzens condensation of chloroacetonitrile [14, 15]. The results are presented in Table 5.8. 

Likewise, BTEAC catalyzes the related condensation of chloromethyl p-tolyl sulfone with carbonyl compounds (see Eq. 5.10). The synthesis of several a, /3-epoxy-sulfones are recorded in Table 5.9. 

Renaud, R and Schubert, S., Radical reductive alkylation of enamines with chloromethyl p-tolyl sulfone, a chain radical process, Angew. Chem. Lnt. Ed. Engl, 29, 433, 1990 idem., Radikahsche reduktiveAlkyherungvonEnaminenmitChlormethyl-p-tolylsulfon,Angew. Chem., 102,416,1990. 

This sulfoxide-magnesium exchange reaction could be successfully applied to a new synthesis of allenes (Scheme 3.12) [6]. The procedure is a novel method for synthesis of allenes from three components, ketones, chloromethyl p-tolyl sulfoxide, and sulfones, in relatively short steps. A key step is an attack of the lithium a-sulfonyl carbanion on the electron-deficient carbene carbon. /1-Elimination of the sulfoxyl group then occurs to give the allene. 

In an attempt to further extend the foregoing methodology to include the preparation of o,p-epoxy sulfides, the condensation of chloromethyl p-tolyl sulfide and benzaldehyde using a protocol similar to that employed successfully in the sulfone case (Bu OK) gave only poor conversion to the desired epoxide. However, addition of the hindered amine base 1,4-diazabicyclo[2.2.2]octane (DABCO) results in the formation of the isomeric expoxides (29) in good yield (equation 9). In the case of benzaldehyde, the cis-epoxide predominates over the trans-epoxide (29b 82% versus 18%), while in the corresponding condensation with pivalaldehyde, the only epoxy sulfide obtained is the cis isomer (29c). Several attempts to effect an analogous reaction with ketones were unsuccessful formation of (30) (displacement-elimination) becomes the favored process (equation 10). 

Carbanions of chloromethyl aryl sulfone (Ar = Ph or p-tolyl) in DMSO-Bu OK react with 9,10-anthraquinone by vicarious nucleophilic substitution or addition to the... 

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