Organobismuth halides

Organobismuth(III) halides may be prepared by elimination of aryl halide from triarylbismuth(V) dichlorides or dibromides upon heating (equation 4). Presumably, a bis-muth(V) compound is the intermediate when triarylbismuth compounds are treated with iodine or when trialkylbis-muth complexes are treated with chlorine, bromine, or iodine, but the intermediates have not been isolated and organobismuth halides are obtained directly (equation 5). The tris(trifluoromethyl)bismuth behaves like the trialkyl compounds without the observation of a bismuth(V) intermediate. ... 

It has been illustrated by structural studies that the organobismuth halides tend to self-organize in the solid state. Their number is, however, limited to simpler representatives. Sterically demanding groups probably prevent association. 

Fig. 2 Plausible mechanism for the cross-coupling reaction of organobismuth compounds with organic halides and triflates...

Organobismuth(in) complexes may mediate a number of reactions involving aUyhc compounds and aldehydes. In these reactions, an aUyl halide is treated with a bismuth(lll) salt such as Bids and a reducing agent (Zn, Fe, or Al) in the presence of an aldehyde (equation 13). A likely reaction... 

Mixed halides such as 56 and 57 give organobismuth compounds bearing Bi-metal bonds upon treatment with nucleophiles (equations 158 and 159 ). 

The Pd-catalyzed cross-coupling reaction of an organobismuth compound was first recorded by Barton and co-workers in 1988. Thus, the reaction of triphenylbismuth with acyl halides took place in the presence of catalytic amounts of Pd(OAc>2 and... 

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