Oxaphosphorinanone oxides

On the other hand, Pd-catalysed phosphaannulation of phosphonic acids (610) by carbonylation of C-H bonds afforded oxaphosphorinanone oxides (611) in moderate to good yield (Scheme 178). ... 

Besides the cyclic acid anhydrides, the oxaphosphorinanone oxides, which are bioisostere of acid anhydrides and inhibitors of P-lactamase [47], have also been synthesized by palladium-catalyzed C-H carbonylation of phosphonic and phos-phinic acids (Scheme 3.23) [48]. In the presence of 5mol% Pd(OAc)2, l.Sequiv. of PhI(OAc)2, and l.Sequiv. of AgOAc, benzylphosphonic and phosphinic acid derivatives could give the corresponding oxaphosphorinanone oxides in moderate to high yields by incorporation of a carbonyl group. 

Scheme 3.23 Pd-catalyzed C-H carbonylation synthesis of oxaphosphorinanone oxides.

Scheme 3.24 Pd-catalyzed synthesis of oxaphosphorinanone oxides via C-H carbonylation.

In 2014, Lee and coworkers also reported an efficient phosphaannulation by Pd-catalyzed carbonylation of C-H bonds of phosphonic and phosphinic acids for the synthesis of oxaphosphorinanone oxides (Scheme 4.29) [43]. In the reaction, AgOAc and PhI(OAc)2 gave the best result. In the transformation, ethyl hydrogen benzylphosphonate and methyl-substituted phosphonate were totally ineffective. It indicated that introduction of two substituents at the a-position was essential for successful carbonylation. Both electron-donating and electron-withdrawing groups on the aryl ring were tolerated. 

Lee et al. in 2014 exploited the phosphonic and phosphinic acid as the directing group for the carbonylative phosphaannulation in the presence of palladium catalyst, thus a series of oxaphosphorinanone oxides were obtained... 

Table 15.33 Pd(ll)-catalyzed carbonyiative phosphaannulation of phosphonic and phos-phinic acid to prepare oxaphosphorinanone oxides . ...

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