Alkylation xanthate-mediated radical

Organosulfone-mediated allylation, vinylation and azidation represent very effective tin-free radical processes. However, the reported methods do not work well with primary alkyl iodides and xanthate as radical precursor, owing to in-... 

Et3B and FeS04-7H20 have also been used to initiate a xanthate-mediated intermolecular oxidative radical alkylation with moderate success [14]. In this... 

In the second case, the soluble polymer 68 was treated with 10-undecenoyl chloride 72 to form the resin-bound alkene 73 (Scheme 16) [11]. Radical addition of xanthate 74, mediated by lauroyl peroxide (50 mol %), gave the product xanthate 75 and tetralone 76 as a 9 1 mixture, in an overall yield of 70%. By-product 76 is formed by intramolecular addition of the intermediate alkyl radical to the aromatic ring competing with intermolecular chain transfer. It was not possible to achieve complete consumption of 73 in this case possibly due to the decrease in the rate of the intermolecular radical addition step as the alkene was consumed. These experiments show, however, that xan-... 

Along with tin hydride-mediated arylations, electrochemical [61], photochemical [62] and iodine transfer methods [63] have each been successfully used for the generation of alkyl radicals in homolyhc aromahc subshtuhons. Moreover, nucleophilic a-oxyalkyl radicals, prepared from the corresponding aldehydes by treatment with either samarium diiodide [64] or stannyl radicals [65], reacted with arenes to afford the homolyhc subshtuhon products. In a series of reports, Zard highlighted the potenhal of xanthates as alkyl radical precursors in homolytic aromatic subshtuhons [66]. 

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