413 research outputs found
Some aspects of radical chemistry in the assembly of complex molecular architectures
International audienceThis review article describes briefly some of the radical processes developed in the authors' laboratory as they pertain to the concise assembly of complex molecular scaffolds. The emphasis is placed on the use of nitrogen-centred radicals, on the degenerate addition-transfer of xanthates, especially on its potential for intermolecular carbon-carbon bond formation, and on the generation and capture of radicals through electron transfer processes
Fun with radicals: Some new perspectives for organic synthesis
International audienceThe degenerative radical addition-transfer of xanthates onto alkenes allows the rapid assembly of richly functionalized structures. Various families of open-chain, cyclic, and polycyclic compounds can thus be readily accessed. Furthermore, the process can be extended to the synthesis or modification of aromatic and heteroaromatic derivatives by exploiting the possibility of using peroxides both as initiators and stoichiometric oxidants. The modification of existing polymers and the controlled synthesis of block polymers by what is now known as the RAFT/MADIX (reversible addition-fragmentation transfer/ macromolecular design by interchange of xanthate) process is described briefly. © 2010 IUPAC
A convergent, modular access to α-chloro-trifluoromethyl derivatives and to 1,1-difluoroalkenes
International audienceAn efficient protocol for the preparation of S-(1-chloro-2,2,2-trifluoroethyl)-O-ethyl xanthate is reported. This reagent serves as a versatile precursor of highly functionalized gem-difluoroalkenes through various inter- and intramolecular radical reactions and subsequent reduction with activated magnesium metal. (C) 2014 Elsevier Ltd. All rights reserved
Rapid assembly of polycyclic structures via sigmatropic rearrangement of s-propargyl xanthates
International audienceUpon heating in chlorobenzene, propargyl xanthates yield the corresponding 4,5-bis(alkylidene)-1,3-dithiolan-2-ones which are trapped by unactivated olefins in an intramolecular Diels-Alder cycloaddition yielding interesting polycyclic structures
A flexible radical approach to 5-substituted 4,5-dihydro-3H-pyrido[4,3-b]azepin-2-ones. Some mechanistic observations on the radical cyclisation-aromatisation process
International audienceVariously substituted novel dihydropyridoazepinones have been prepared by an intermolecular radical addition followed by a radical cyclisation on a pyridine ring. The latter process involved the use of a combination of two different peroxides, an experimental contrivance resulting from a careful product analysis and a better understanding of the cyclisation step. © 2012 Elsevier Ltd. All rights reserved
Reversible Reservoirs for Radicals. Some New Perspectives for Organic Synthesis and for Polymer Chemistry
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Radicals in Action. New Perspectives for Organic Synthesis and Medicinal Chemistry.
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Reversible Reservoirs for Radicals. A Powerful Strategy for the Construction of Carbon-Carbon Bonds
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