20928-02-3Relevant academic research and scientific papers
Synthesis of hindered biaryls via aryne addition and in situ dimerization
García-López, José-Antonio,Cetin, Meliha,Greaney, Michael F.
supporting information, p. 2649 - 2651 (2015/06/16)
Benzynes generated under Knochel conditions from 2-iodophenylsulfonates and iPrMgCl smoothly add to thiol, selenol, and amine nucleophiles. Treatment of the resulting aryl Grignard intermediate with a copper salt and an organic oxidant then affords symmetrical biaryls in good yield. 3-Substituted arynes undergo regioselective addition, enabling synthesis of atropisomeric biaryls with chelating S, Se, or N groups in the 2,2′ positions.
Reactions of 2-(pyrrol-1-yl)benzyl radicals and related species under flash vacuum pyrolysis conditions
Cadogan,Clark, Bernard A. J.,Ford, Daniel,MacDonald, Ranald J.,MacPherson, Andrew D.,McNab, Hamish,Nicolson, Iain S.,Reed, David,Sommerville, Craig C.
experimental part, p. 5173 - 5183 (2010/04/03)
2-(Pyrrol-1-yl)phenoxyl, aminyl, thiophenoxyl and benzyl radicals 2a-2d, respectively, were generated in the gas-phase under flash vacuum pyrolysis conditions. In all cases except the phenoxyl, cyclisation took place providing acceptable synthetic routes to the fused heterocycles 11, 14 and 15, respectively. Only sigmatropic rearrangement products were isolated, in low yields, from the phenoxyl 2a. The pyrrolo[1,2-a]benzimidazole 11 adopts the 1H-tautomer exclusively in chloroform solution. Electrophilic substitution reactions of pyrrolo[2,1-b]benzothiophene 14 were studied, including protonation, deuterium exchange, Vilsmeier formylation and reaction with dimethyl acetylenedicarboxylate. 2-(2,5-Diarylpyrrol-1-yl)thiophenoxyl, phenoxyl and aminyl radicals 23a-f, were also generated in the gas-phase under similar conditions. The thiophenoxyls 23a/b gave extremely complex pyrolysate mixtures in which primary cyclisation products were formed by attack of the radical at the pyrrrole ring and attack at the ipso-, ortho- and meta- positions of the aryl ring. Secondary pyrolysis products were obtained by specific sigmatropic shifts of the N-aryl group. The 2,5-di(thien-2-yl)thiophenoxyl radical 23c gave the pyrrolobenzothiazole 31c as the only cyclisation product in low yield. FVP of the phenoxyl and aminyl radical generators 26d and 26f, respectively, gave 3-arylpyrrolo[1,2-f]phenanthridines 46d and 46f, respectively, by a hydrogen transfer-cyclisation mechanism.
A MILD AND EFFICIENT SRN1 APPROACH TO DIARYL SULFIDES FROM ARENEDIAZONIUM TETRAFLUOROBORATES
Petrillo, Giovanni,Novi, Marino,Garbarino, Giacomo,Dell'Erba, Carlo
, p. 4007 - 4016 (2007/10/02)
The reaction between arenediazonium tetrafluoroborates and sodium arenethiolates in Me2SO at 25 deg C represent an efficient access to diaryl sulfides.A number of evidences suggest the occurance of a radical, radical-anion SRN1 mechanism, the arenethiolate acting both as electron donor and as aryl-radical trapping nucleophile.Valuable improvements with respect to recent SRN1 syntheses of diaryl sulfides from haloarenes are represented, inter alia, by the compatibility of both electron-withdrawing and relasing substituents as well as by the intensivity to steric hindrance in the diazonium salt.When the arenediazonium ion bears another SRN1 leaving group (such as Cl, Br, or I) disubstitution products are predominantly formed.
