Studies On The Application Of Arynes In Organic Synthesis

Arynes as useful reactive intermediates have been received considerable attentions in synthetic application. Recently, the chemistry of arynes has been extended to insertion of element-elementσ-bond, multi-component reactions and transition-metal-catalyzed reactions to synthesize the complex organic molecules or polysubstituted arenes, which are difficult to prepare by other strategies.Firstly, we have developed Larock's method for O-Arylation of a variety of carboxylic acids and arynes using (phenyl)[2-(trimethylsilyl)phenyl]iodonium triflate as a precursor. Our method has more broad applications than the Larock's method.Secondly, a novel synthesis of spiro[imidazolidine-2, 3'-benzo[b]thiophene] by one-pot reaction of arynes, aryl isothiocyante and N-heterocyclic carbenes has been developed. It is the first example of reaction of 1, 3-dipolar compounds containing of a central carbon with arynes.Finally, a novel three-component reaction of arynes,β-keto sulfones and Michael-type acceptors for the synthesis of polysubstituted naphthols and naphthalenes has been developed. The reaction may proceed via nucleophilic attack on the arynes, intramolecular nucleophilic substitution, Michael addition, ring closure and elimilation. It is the first example of successful trapping of the intermediate benzyl anion with electrophiles. To understand the mechanism better, the insertion ofβ-keto sulfones to arynes was also examined.