Bismuthonium

Bismuthonium Ylides. Prior to 1988 the only bismuthonium yhdes known were (1) and (2). 

Stmcture (1) is an unstable blue soHd which caimot be obtained in a pure state (167) stmcture (2) [105071-90-7] however, is stable (168). Stmcture (2) was obtained from triphenylbismuth carbonate and dimedone. More recendy a number of bismuthonium yUdes, eg, (3) [119016-81 -8] (169), have been prepared and their reactions studied. 

Bismuthonium ylides, 4 34 Bismuth(III) oxide, 4 23-24 Bismuth oxide(l l), 4 23 Bismuth oxide(l 2), 4 23 Bismuth oxide(2 4), 4 23 Bismuth oxide(3 5), 4 23 Bismuth oxide(4 9), 4 23 Bismuth oxide halides, 4 23 Bismuth oxides, 4 23-24 Bismuth oxybromide, 4 23 Bismuth oxychloride, 4 23 physical properties of, 4 20t pigment used in makeups, 7 836t Bismuth oxyfluoride, 4 23 Bismuth oxyiodide, 4 23 Bismuth pentafluoride, 4 22 physical properties of, 4 20t Bismuth phosphate, 4 25... 

Scheme 23 Competitive oxidations between primary and secondary benzyl alcohols by using the bulky bismuthonium salts [90]...

The reaction of alkenyltriphenylbismuthonium salt with ethyl acrylate in the presence of Pd(OAc)2 (2 mol%) afforded both alkenylated and phenylated products in low yields (Scheme 4) [13]. In addition, ligand coupling products of the bismuthonium salt were also formed. 

The reaction of the same bismuthonium ylide with isothiocyanates in the presence of a copper(H) catalyst afforded the sulfur-incorporated spiro-cyclic compound as the main product, in addition to a small amount of carbon-carbon bond formed products (Scheme 12) [28],... 

R = Php-Tol, 4-CIC6H4, hexyl, Ph C02CH2 Scheme 11 Reaction of bismuthonium ylide with alkynes... 

Scheme 12 Reaction of bismuthonium ylide with isothiocyanates...

Quaternary bismuth compounds are generally unstable. When the anionic ligand is chloride or bromide, the compounds decompose spontaneously on standing azides and selenocyanates decompose more rapidly. The perchlorates, tetrafluoroborates, and hexafluorophophates, however, are considerably more stable but eventually decompose. The vibrational spectra of the latter compounds show the presence of the free ion and are consistent with a tetrahedral BiC4 skeleton for the cation. The acetonyltriphenyl compounds, [(C(5H5)3BiCH2COCH3]Y, where Y is C10- 4 or BF- 4, also appear to be true bismuthonium salts. 

Lloyd, D., Gosney, I. and Ormiston, R.A. (1987) Arsonium ylides (with some mention also of arsinimines, stibonium and bismuthonium ylides). Chemical Society Reviews, 16, 45-74. 

Bismuthonium salts in C-C bond formation, 9, 446 in C-heteroatom bond formation, 9, 449 Bismuth ylides... 

Carbon functional groups, attachment to polysilanes, 3, 585 Carbon-heteroatom bond formation via antimony(III) compounds, 9, 428 via antimony(V) compounds, 9, 432 via bismuth(III) compounds characteristics, 9, 440 with copper catalysts, 9, 442 non-catalyzed reactions, 9, 443 with bismuth(V) compounds, 9, 450 with bismuthonium salts, 9, 449 with bismuth ylides, 9, 450 Carbon-heteroatom ligands in tetraosmium clusters, 6, 967 in tetraruthenium clusters, 6, 960... 

Carbon-carbon bond-forming reactions using bismuthonium salts 446... 

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