Water-soluble non-ionic triarylbismuthanes. First synthesis and properties
Abstract
The synthesis and properties of some new water-soluble non-ionic triarylbismuthanes are described. o-, m- and p-Tris(methoxymethoxyphenyl)bismuthanes 1a–c are prepared from BiCl3 and the corresponding organolithium or Grignard reagents. Oxidative chlorination of 1a–c with SO2Cl2 affords tris(methoxymethoxyphenyl)bismuth dichlorides 2a–c, which are deprotected by aqueous HCl to give tris(hydroxyphenyl)bismuth dichlorides 3a–c. Treatment of tris(3-hydroxyphenyl)bismuth dichloride 3b with NH2NH2 yields tris(3-hydroxyphenyl)bismuthane 5, which dissolves in dilute aqueous NaOH. N,N-Bis(2-tert-butyldimethylsiloxyethyl)benzenesulfonamide, prepared from benzenesulfonyl chloride and silyl-protected diethanolamine, is ortho-lithiated and reacted with ⅓ equiv. of BiCl3 to give Ar3Bi 9a {Ar = 2-[N,N-bis(2-tert-butyldimethylsiloxyethyl)sulfamoyl]phenyl}. m-Phenylene-bridged Bi2- and Bi3-polybismuthanes 12 and 13 are prepared by the reaction between ortho-lithiated 9a and Ar2BiI 10. Desilylation of 9a, 12 and 13 by Bu4NF or p-TsOH·H2O in EtOH leads to the corresponding bismuthanepolyols 11, 14 and 15. The reaction between benzene-1,3-disulfonamide 16 bearing the silyl-protected bis(2-hydroxyethyl)amino side chains and ⅓ equiv. of BiCl3 affords tris{2,4-bis[N,N-bis(2-tert-butyldimethylsiloxyethyl)sulfamoyl]phenyl}bismuthane 17, which is deprotected by p-TsOH·H2O to yield tris{2,4-bis[N,N-bis(2-hydroxyethyl)sulfamoyl]phenyl}bismuthane 18. Compounds 11, 14 and 15 are only slightly soluble in water, but compound 18 is fairly soluble.