Abstraction hydride, photochemical

Heterocyclic sulphoxides 65 mass spectra of 130-132 Hexahydronaphthalenols, synthesis of 310 Hofmann elimination 953 HOMO energies 1048, 1049 Homolytic substitution 1109 intramolecular 846 Horner-Wittig reaction 333 Hot electrons 892, 893 HSAB theory 282, 549 Hydrides, as reducing agents 934-941, 959 Hydrogen abstraction, photochemical 874, 876, 877, 879, 880... 

Hence, most photochemical precursors of radicals in solution (peroxides, azo compounds, most halides, etc.) are not generally suitable for in situ generation of these species in confined environments such as matrices (of course reagents that generate radicals by abstraction, such as the popular trialkyl tin hydrides, are also excluded from matrix isolation). 

Photochemical coupling of the hydride of the six-membered ring, using t-butoxy radical as a hydrogen-abstracting reagent, produces a bi-ring compound ... 

Radicals can be generated by homolysis of weak a-bonds. Homolysis is effected by photochemical, thermal or redox (electron transfer) methods. A common method to initiate a radical reaction is to warm a peroxide such as benzoyl peroxide or azobi-sisobutyronitrile (AIBN) 1 (4.2). The radical -C(CN)Me2 generated from AIBN is rather umeactive, but is capable of abstracting a hydrogen atom from weakly bonded molecules such as tributyltin hydride (4.3). The resulting tributyltin radical reacts readily with alkyl halides, selenides and other substrates to form a carbon-centred radical. 

Electrochemical functionalization methods 3 Electrochemical reaction 6 Photochemical functionalization methods 4 Photochemical reaction 6 Silicon-carbon bond formation 1 Thermal functionalization methods 3 Thermal-Grignard and organolithium reagents 5 Thermal-heat reaction 3 Thermal-hydride abstraction 5 Thermal-Lewis acid catalysis 4 Thermal-radical initiators 3 Thermal-transition metal catalysis 4... 

For example, three hydride abstraction reactions were separated from the other reactions and put into one class, photochemical reactions were grouped in another, etc. The two largest classes contained 32 reactions each and were definably Michael additions, as in... 

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