Hydrophosphorylations nickel

Nickel complexes have proved to be active for hydrophosphorylation of alkynes [17a, 25]. Not only the five-membered phosphonate but also commercially available dialkyl phosphonates readily react in the presence of... 

Unprecedented control of selectivity has been observed in the Ni(acac)2/DIBAL hydrophosphorylation of allq nes. The unique selectivity switch allowed controlling of the reaction in the desired way by a simple change of the amount of nickel catalyst. Thus, use of the 9 mol% of Ni(acac)2/DIBAL system led to the sy -addition product (318) while 1 mol% led to alkylbisphosphonate (319) (Scheme 87). Moreover, the utility of the synthesised products for the fire protection of cotton materials has also been demonstrated. ... 

Hydrophosphorylation of alkynes via external attack of //-phosphonate to an (alkyne)metal complex is a possible pathway, although the possibility has been concluded to be less likely as far as the nickel-catalyzed reaction is concerned [12]. However, such a process appears to proceed in early transition metal carbonyl-catalyzed reactiOTis [19]. For instance, refluxing a mixture of phenylacetylene, HP(0)(0Et)2, and Mo(CO)fi (10 mol%) affords the franr-addition product... 

Due to the successful development of the catalyzed hydrophosphorylation, its extension to functionalized alkynes is becoming of interest. Nickel-catalyzed addition of //-phosphonate (and also //-phosphinate and sec-phosphine oxide) to propargyhc alcohols is an interesting example, as discussed later (Sect. 4). 

Compound 7, a proposed structure for the antibiotic A53868, has been synthesized via a sequence of reactions involving nickel-catalyzed hydrophosphorylation of a propargyl amine derivative in the presence of diphenylphosphinic acid (Scheme 16) [21]. Although the compound is not identified with the natural A53868, it also displays antimicrobial activity against Escherichia coli. 

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