2582-56-1Relevant articles and documents
Cross-coupling strategy for the synthesis of diazocines
Eleya, Nadi,Li, Shuo,Staubitz, Anne
supporting information, p. 1624 - 1627 (2020/03/13)
Ethylene bridged azobenzenes are novel, promising molecular switches that are thermodynamically more stable in the (Z) than in the (E) configuration, contrary to the linear azobenzene. However, their previous synthetic routes were often not general, and yields were poorly reproducible, and sometimes very low. Here we present a new synthetic strategy that is both versatile and reliable. Starting from widely available 2-bromobenzyl bromides, the designated molecules can be obtained in three simple steps.
Straightforward synthesis of substituted dibenzyl derivatives
Mboyi, Clève D.,Gaillard, Sylvain,Mabaye, Mbaye D.,Pannetier, Nicolas,Renaud, Jean-Luc
, p. 4875 - 4882 (2013/06/26)
The C-C bond formation by homogeneous catalysis is a powerful tool in organic synthesis. The replacement of noble metal by cheaper one for already reported methodologies is of interest for an economical purpose. The attractivity of such replacement is also enhanced if a first raw transition metal is found to be active in several processes. This work demonstrates that a common nickel complex can be used for a two-step cross-coupling procedure, namely a homocoupling reaction of benzyl derivatives and a subsequent Suzuki reaction. These consecutive reactions permit the synthesis of new polyfunctionalized dibenzyl compounds.
Flash vacuum pyrolysis over magnesium. Part 1 - Pyrolysis of benzylic, other aryl/alkyl and aliphatic halides
Aitken, R. Alan,Hodgson, Philip K.G.,Morrison, John J.,Oyewale, Adebayo O.
, p. 402 - 415 (2007/10/03)
Flash vacuum pyrolysis over a bed of freshly sublimed magnesium on glass wool results in efficient coupling of benzyl halides to give the corresponding bibenzyls. Where an ortho halogen substituent is present further dehalogenation gives some dihydroanthracene and anthracene. Efficient coupling is also observed for halomethylnaphthalenes and halodiphenylmethanes while chlorotriphenylmethane gives 4,4′-bis(diphenylmethyl)biphenyl. By using α,α′-dihalo-o-xylenes, benzocyclobutenes are obtained in good yield, while the isomeric α,α′-dihalo-p-xylenes give a range of high thermal stability polymers by polymerisation of the initially formed p-xylylenes. Other haloalkylbenzenes undergo largely dehydrohalogenation where this is possible, in some cases resulting in cyclisation. Deoxygenation is also observed with haloalkyl phenyl ketones to give phenylalkynes as well as other products. With simple alkyl halides there is efficient elimination of HCl or HBr to give alkenes. For aliphatic dihalides this also occurs to give dienes but there is also cyclisation to give cycloalkanes and dehalogenation with hydrogen atom transfer to give alkenes in some cases. For 5-bromopent-1-ene the products are those expected from a radical pathway but for 6-bromohex-1-ene they are clearly not. For 2,2-dichloropropane and 1,1-dichloropropane elimination of HCl occurs but for 1,1-dichlorobutane, -pentane and -hexane partial hydrolysis followed by elimination of HCl gives E, E-, E,Z- and Z,Z- isomers of the dialk-1-enyl ethers and fully assigned 13C NMR data are presented for these. With 6-chlorohex-1-yne and 7-chlorohept-1-yne there is cyclisation to give methylenecycloalkanes and -cycloalkynes. The behaviour of 1,2-dibromocyclohexane and 1,2-dichlorocyclooctane under these conditions is also examined. Various pieces of evidence are presented that suggest that these processes do not involve generation of free gas-phase radicals but rather surface-adsorbed organometallic species.
