2-(Trimethylsilyl)aryl trifluoromethanesulfonates as aryne precursors aiming to the preparation of functionalized (hetero)aromatic compounds and syntheses of bioactive natural products

Abstract

Benzyne and its derivatives, called arynes, are highly reactive intermediates, with recognized importance in organic chemistry, successfully employed in syntheses of natural products and preparations of functional materials. In this sense, TMS-aryl trifluoromethanesulfonates have emerged as an important alternative for the formation of benzyne and arynes under mild reaction conditions, enlarging the scope of benzyne chemistry applications in preparative organic chemistry. Within this context, we intend to develop the reaction between TMS-aryl trifluoromethanesulfonates and N-sulfonyl-1,2,3-triazoles in the presence of a source of fluoride ions, using a transition metal as a catalyst, to obtain substituted indole compounds. In parallel, we wish to complete the enantioselective total synthesis of the aporphine alkaloid (S)-nuciferine, employing in the key steps benzyne chemistry and enantioselective hydrogenation. At the same time, we intend to carry out the total synthesis of the ergoline alkaloid (±)-lisergic acid, employing in the key steps Heck reaction and transformation promoted by the formation of aryne. In addition, we wish to perform the semi-syntheses of (-)-cannabidiol and of (+)-cannabidiol investigating mainly the optimization of their corresponding key steps, aiming at pharmacological studies. For the same purpose, we intend to explore the three-component reaction involving TMS-aryl trifluoromethanesulfonates, cyclic allyl acetates, and trifluoromethyl benzoate using a source of fluoride ions, promoting the formation of substituted arylcyclohexene compounds, which comprise the structural core of cannabidiol. (AU)