Grignard reagents, reaction with sulfonium

Unactivated aryl iodides undergo the conversion Arl — ArCHj when treated with tris(diethylamino)sulfonium difluorotrimethylsilicate and a palladium catalyst.131 A number of methods, all catalyzed by palladium complexes, have been used to prepare unsymmetrical biaryls (see also 3-16). In these methods, aryl bromides or iodides are coupled with aryl Grignard reagents,152 with arylboronic acids ArB(OH)2,153 with aryltin compounds Ar-SnR3,154 and with arylmercury compounds.155 Unsymmetrical binaphthyls were synthesized by photochemically stimulated reaction of naphthyl iodides with naphthoxide ions in an SrnI reaction.156 Grignard reagents also couple with aryl halides without a palladium catalyst, by the benzyne mechanism.157 OS VI, 916 65, 108 66, 67. 

The reaction of LVII" and some related heterocycles with a large number of nucleophiles has been investigated thoroughly. Among the nucleophiles, which with few exceptions form sulfonium salts by their reaction with LVII", are water [194, 195], carboxylate ions [196, 197], pyridine [198], organometallic compounds like dialkylmercury and dialkylzinc [199], and Grignard reagents [200], alkenes and alkynes [201], and various aromatic compounds [202-204]. 

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