Objective
The aim of this joint research project is to carry out a sys tematic investigation of a new approach to the synthesis of olefinic chalcogen (S, Se, Te) derivatives containing addi tional heteroatomic moieties (B, Al, Si, Sn and halogens) in view of transforming them further in highly regio- and stereo selective manner into (functionalized) tri- and tetrasubstitu ted alkenes. The new approach is based on the application of transition metal catalysis in organochalcogen chemistry with particular emphasis on: i) the palladium catalyzed addition of chalcogen reagents, such as organic selenenylsulfides, diselenides (sym metrical and unsymmetrical), tellurenylselenides, silylsul fides, stannylsulfides, stannylselenides, thioboranes, etc., to alkynes, chalcogenoalkynes, halogenoalkynes, silyl- and stannylalkynes in view of obtaining the desired polyfunctiona lized alkenes in a regio- and stereocontrolled fashion; ii) the selective activation of the various heteroatomic moieties present in the above alkenes in order to allow their replace ment by suitable carbon moieties. Part i) requires the clean syntheses of the necessary chalcogen-main group metal (B, Al, Si, Sn) containing reagents, either by already known methods, or by new ones presently being investigated in two of the par tner laboratories (Irkutsk, Namur). Furthermore, part i) will also concentrate on gaining mechanistic insight into the addition reactions by studying the real nature of the interm ediates formed from Pd(II) complexes and/or Pd(0)complexes and the chalcogen reagents. Part ii) will obviously take advan tage of the fact that organosulfur and organoselenium chemi stry are well explored areas of organic synthesis, and organ otellurium chemistry is rapidly developping at present. Also, a great amount of knowledge has been accumulated during the last two decades about the activation of B, Al, Si and Sn mo ieties in organic compounds in view of facilitating C-C bond formation. However, little is known on the chemoselectivity of the activation processes when both these metals and chal cogen and/or halogen atoms are present. Finding appropriate solutions in this area will be one of the major tasks of the project. As far as the time schedule allows, investigations will be extended to the transition metal (Ni, Pd, Pt) cataly zed cross-coupling and carbonylative cross-coupling reactions between vinyl, aryl and heteroaryl derivatives and some of the chalcogen reagents.
The preliminary results already obtained by some of the part ner teams, the complementary expertise of the latters, as will as the data existing in the literature and referred to in the WORK PROGRAMME confer high levels of viability and feasi bility to this project within the available time periode of 2 years.
Topic(s)
Call for proposal
Data not availableFunding Scheme
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5000 Namur
Belgium