Phosphonites reduction

Wasserscheid et al. [116] incorporated guanidinium groups into a Xantphos skeleton via the corresponding bis(diethyl phosphonite), reduction, and final Pd-catalyzed arylation (Scheme 2.33). In the rhodium-catalyzed hydroformylation of... 

Two preparations of diesters of phosphonous acid have been reported, - One of these, which claims to be the first preparation of these derivatives, involves the reaction of ammonium hypophosphite with triaikylsilylamines to give bis(trialkylsilyl) esters (127) in excellent yield. These compounds are extremely reactive, e.g. they are spontaneously inflammable in air. Dialkyl phosphonites (128) have also been prepared by the reduction of... 

As illustrated in Fig. 6, imines serve as important intermediates for a number of solid-phase syntheses. Additional uses for these versatile intermediates are described in Fig. 9. Resin-bound thioketene acetals have been shown to condense with imines to provide, after reductive cleavage, a route to substituted aminoalcohols 6 [45], Aminophosphinic acids 7 were prepared by allowing bis(trimethylsilyl)phosphonite to react with resin-bound imines [46],... 

The rhodium(I)-catalyzed reduction of ketones with silanes is also subject to enantioselection by chiral ligands, which can be a bipyridine derivative, cyclic phosphonites and phosphites, " or diferrocenyl dichalcogenides. ... 

The phosphonite type is much less effective than the phosphite type in the stabilization of poly(aryl ether ketonejs. However, the addition of organic phosphorus compounds in conjunction with an organic acid, such as oxalic acid or acetic acid results in a very significant reduction in melt viscosity, even where the phosphorus compound alone has a detrimental effect. The results using the stabilizers can be summarized as follows ... 

In 1970, Tavs reported the first nickel-catalyzed arylation of trialkyl phosphites or dialkyl aryl phosphonites with aryl bromides [242] (Scheme 20.72). In this reaction, trialkyl phosphite, a phosphorylating agent, plays a crucial role in the reduction of Ni(II) to active Ni(0) complex [243]. 

In the case of copolymerization of vinylphosphonic acid monoethyl ester (92) with cyclic phosphonites (86), the alternating copolymer (93) having two kinds of phosphorus atoms in the main chain was formed. During the copolymerization, monomer 92 was reduced involving a hydrogen-transfer process and monomer 86 was oxidized the oxidation state of the phosphorus atom of monomer 86 changed, therefore, from trivalent to pentavalent ( oxidation-reduction copolymerization ). ... 

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