Phenyl diselenide

When 59 or 60 are treated with a reducing agent such as hydrazine or triphenyl-phosphine, the Se-N bond is cleaved to give 2-(carbamoyl)phenyl diselenides [92], The ring cleavage with thiols leads to the selenosulfides [10, 97],... 

Another preparative route for synthesis of benzisoselenazol-3(27/)-ones is based on the lithiation of the benzamides, followed by the conversion of dilithium derivatives by direct treatment with selenium, or via 2-[(carbamoyl)phenyl]methyl selenides or 2,2 -bis[(carbamoyl)phenyl] diselenides [167-172], These diselenides are oxidatively cyclized and, depending on the oxidant used, benzisoselenazol-3 (2H)-ones or their 1-oxides are produced in high yields [92, 173],... 

Pyrazino 2,3-fc][l,4 bcnzoselenazine (146) gave 2,5-dichloro-3-[3-chloro-6-(chloroseleno)anilino]pyrazine (147) (MeCN, Cl2j —75% characterized but structure not fully confirmed), and thence bis[4-chloro-2-(3,6-dichloropy-razin-2-ylamino)phenyl] diselenide (148) (Me2SO, 20°C, 15 min % ClCH2SMe formed structure confirmed).351... 

Compound 45 was easily synthesized from bis[(2-chloromethyl)phenyl] diselenide 149 by a reduction with sodium borohydride. The 4-deuterated derivative has been prepared in a similar way by using LiAlD4 followed by treatment with thionyl chloride < 1992PS125, 1996BCJ1825>. 

A convenient and inexpensive method to transform electron rich aromatic aldehydes to phenols," or a,p-unsaturated aldehydes to vinyl formates, utilizes 30% hydrogen peroxide catdyzed by bis(n-nitro-phenyl) diselenide. A two-step formylation/MCPBA oxidation procedure (Scheme 25) was utilized by Kishi and coworkers in the 100 g scale conversion of 2,6-dimethoxytoluene to the mitomycin precursor (76). An organic peroxy acid was not required for the conversion of 9-formyl-6-methylellipticine (77) to... 

Aryl selenium compounds also form adducts with hydrogen peroxide, ArSe (O)OOH, that are able to carry out epoxidation [188,189], albeit at low rates [190,191]. Improvements can be made by substitution of the aromatic ring with electron-withdrawing trifluoromethyl groups [192], for example, to form the lizs-[3,5-Ws-(trifluoromethyl)phenyl]diselenide. 

Oxidation catalyst. These compounds (1), as well as bis(2-carbamoyl)phenyl diselenides, are very effective catalysts for the oxidation of sulfides, dimethylhydrazones (to nitriles), and azines (to carbonyl comjwunds). 

Tetrahydrofurans The reagent is prepared in situ from bis(2,4,6-triisopropyl-phenyl) diselenide and bromine in dichloromethane at -78°. It promotes a highly stereoselective cyclization of homoallylic alcohols. 

Physical Data bis(4-trimethylsilylphenyl) disulfide is a colorless solid, mp 47-48 °C (hexane), and bis(4-trimethylsilyl-phenyl) diselenide is a yellow solid, tip 45 °C. 

Related Reagents. Bis[4-(tridecafluorohexyl)phenyl] Diselenide l-(Butylseleno)-3,5-bis(heptadecafluorooctyl)-ben-zene l-(Butylseleno)-2,4-bis(heptadecafluorooctyl)benzene. 

Phenethyl propionate 8880 Phenyl diselenide 4477 Phosphoramidothioic acid, 0,5- ... 

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