Let the sunshine in! Unactivated alkyl and aryl bromides underwent a light‐enabled reductive radical cyclization in the presence of a dimeric phosphine–gold complex as a photocatalyst (see scheme; X=C(CO2Et)2, NR, O). Sunlight can be used as the energy source for this simple and efficient radical reaction, which does not require potentially hazardous and toxic chemical reagents, such as organostannanes
让阳光照进来!未活化的烷基和芳基溴化物在二聚膦-金络合物作为光催化剂的情况下进行了光活化的还原性自由基环化反应(见方案; X = C(CO 2 Et)2,NR,O)。阳光可以用作此简单有效的自由基反应的能源,该自由基反应不需要潜在危险和有毒的化学试剂,例如有机锡和化学引发剂。
Synthesis of biaryls via intramolecular free radical ipso-substitution reactions
作者:Feroze Ujjainwalla、Maria Lucília E.N. da Mata、Andrew M.K. Pennell、Carmen Escolano、William B. Motherwell、Santiago Vázquez
DOI:10.1016/j.tet.2015.07.048
日期:2015.9
intramolecular freeradical [1,5]-ipso-substitution using sulfonamide and sulfonate derived tethering chains. The overall efficiency of the process is determined by appropriately positioned substituents on the aromatic acceptor ring. The extension of the process to benzylic sulfonates and their corresponding N-methylsulfonamide alternatives as substrates in potential [1,6]-ipso-substitution reactions leads
formation of homocoupled alkane byproducts have been identified in the reduction of bromoalkanes via photoredoxgold catalysis with dimeric Au(I) complexes. This prompted further investigation into the mechanism of formation of these byproducts and the diversity of C–X bonds amenable to this transformation. Examples were found when considering bromoalkanes while a wide variety of iodoarenes underwent this
A novel route to biaryls via intramolecular free radical ipso substitution reactions
作者:William B. Motherwell、Andrew M. K. Pennell
DOI:10.1039/c39910000877
日期:——
A variety of usefully functionalised biaryls may be prepared under neutral conditions by an intramolecular free radicalipsosubstitution reaction at an sp2 sulphonyl substituted carbon atom; the overall efficiency of the process being determined both by the nature and number of atoms linking the two aromatic rings and by appropriately positioned substituents on the aromatic aceeptor ring.
Steric and electronic effects in the synthesis of biaryls and their heterocyclic congeners using intramolecular free radical [1,5] ipso substitution reactions
作者:Maria Lucília E.N da Mata、William B Motherwell、Feroze Ujjainwalla
DOI:10.1016/s0040-4039(96)02236-8
日期:1997.1
intramolecular free radical [1,5] ipso substition using sulfonamide and sulfonate tethering chains, since the introduction of either electron releasing or electron withdrawing groups ortho to the sulfonyl substituted acceptor ring facilitates the overall reaction.