Isoselenocyanates

Few of the many other inorganic compounds of Ge, Sn and Pb call for special comment. Many pseudo-halogen derivatives of Sn, Pb and Pb have been reported, e.g. cyanides, azides, isocyanates, isothiocyanates, isoselenocyanates and alkoxides. ... 

Aliphatic and aromatic isothiocyanates and isoselenocyanates react with benzopentathiepin to give l,3-benzodithiol-2-imines 14.412... 

Phenyl-1,2-dihydro-3//-l,2,4-triazole-3-selenones 130a-d were delivered as minor products from the reaction of a range of acyl chlorides with potassium isoselenocyanate (Equation 40 and Table 23) <2006H(68)1191>. 

Table 23 Reaction of acyl chlorides with potassium isoselenocyanate (Equation 40)...

Selenoureas are prepared by reaction of isoselenocyanates with amines, or by reaction of carbodiimides with a mixture of LiAlH4/Se and by reaction of cyanamides with LiAlH4/Se.267 272 The tyrosinase inhibitory activity and superoxide radical scavenger effect of selenoamides and selenoureas have been investigated (Scheme 84).273 275... 

The synthesis of 1,3-selenazoles from A -phenylimidoyl isoselenocyanates has been reported. N-phenylimidoyl isoselenocyanates 94 are prepared from N-phenylbenzamides 92. Treatment of 92 with thionyl chloride affords N-phenylbenzimidoyl chlorides 93, which yield imidoyl isoselenocyanates 94 on reaction with potassium isoselenocyanate. The imidoyl isoselenocyanates 94 were transformed into selenoureas 95 with either ammonia or primary or secondary amines. Reaction of 95 with an activated bromomethylene compound such as bromoacetophenone in the prescence of a base gave the 1,3-selenazole 97 via the salt 96 <00HCA1576>. 

The synthesis of 1,2,3-selenadiazole derivatives has been reported. The reaction of aroyl chlorides such as 102 with potassium isoselenocyanate and ethyl diazoacetate yielded 5-(aroylimino)-2,5-dihydro-l, 2,3-selenadiazole-4-carboxylate esters such as 104. A reaction mechanism via the initial formation of the corresponding aroyl isoselenocyanate 103 followed by a 1,3-dipolar cycloaddition of the diazo compound with the C=Se bond is proposed <00HCA539>. 

A number of stable niobium(IV) isothiocyanates and less stable isoselenocyanates are known. Rigorous exclusion of water is required to avoid the formation of selenium during the synthesis of the latter.534... 

The Chemistry of Acyl and Sulphonyl Isocyanates, Isothiocyanates, and Isoselenocyanates ... 

A solitary example of this type of ring formation is provided by the reaction of diphenyl-diazomethane with benzoyl isoselenocyanate, which gives the benzo[6 ]selenophene derivative (199) (80JOC4366). 

Table 57 Selected Nickel(II) Complexes with Cyanate, Isothiocyanate and Isoselenocyanate Anions...

TMS isoselenocyanate, Mc3SiNC.Sc, prepared in situ from TMSC1 and excess KSeCN, shows remarkable chemoselectivity104 in the transformation of carbonyl compounds into... 

A convenient approach to synthesize novel selenium-(3-lactams, namely 3-selena-l-dethiacephems 200, was accomplished via the regioselective iodocycli-zation reaction (Scheme 73) [103]. The key starting materials, alkyne-selenoureas 201, for this approach were readily prepared by the A-alkylation reaction of the corresponding previously known propargyl-azetidinones with a wide variety of isoselenocyanates under basic conditions. First, the reaction of (3-alkyne-selenourea... 

In follow-up work by the group, a general method is described to convert cyclic thio- or selenoureas 6 or 7 to 21 or 22 using isothiocyanates or isoselenocyanates (Scheme 3) <1997HAC13>. 

The first route described to nonfused selenazepanes 67 from the aryl isoselenocyanates 65 and the chloro amine 66 by a stepwise amine addition-ring cyclization strategy (Equation 15) <2005TL6723> also has potential for application to the 1,3-thiazepane and 1,3-oxazepane analogues from the corresponding aryl isothiocyanates and aryl isocyanates. 

New substituted selenophenes were prepared from ketene dithioacetals. Isoselenocyanates were used to obtain aminoselenophenes. Starting from substituted methylsulfonylselenophenes, thieno- and selenolo-selenophenes were synthesized [140],... 

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