Sulfones reactions with organomagnesium

A direct transformation of functionalized aromatic/heteroaromatic halides into sul-fones has been performed via reactions of organomagnesium intermediates with sulfur dioxide (Scheme 19).98 The ratio of sulfones has been considerably increased by the use of polar aprotic solvents such as DMF or DMSO and of allylic and primary halides. 

Transition metal-catalyzed cross-coupling reaction has become the most important method for the formation of aryl-aryl bonds. The reaction of aryl halides and sulfonates with organomagnesium compounds is usually referred... 

Reactions of organomagnesium compounds with dialkyl sulfates or alkyl sulfonates often give satisfactory yields of the products of displacement of sulfate or sulfonate. Side-reactions have been observed, but they can often be avoided for example, an excess of the sulfate or sulfonate should be used with Grignard reagents, as some is consumed by nucleophilic attack by halide ion [A]. The dialkyl sulfates are reactive, but hazardous. Toluenesulfonates (tosylates) are less reactive, but their reactions are catalysed by copper complexes the reactions of trifluoromethanesulfonates (triflates) are catalysed by nickel complexes. Reactions of Grignard reagents with secondary tosylates appear to follow an Sn2 mechanism, with inversion of configuration [43],... 

Reactions of organomagnesium compounds with sulfates and sulfonates... 

Recently, the reaction of organolithium compounds with magnesium carboxylates or sulfonates has been used to prepare organomagnesium compounds with increased selectivity towards carbonyl compounds (see Section 6.1) [32],... 

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