Addition reactions of a phosphorus triamide to nitrosoarenes and acylpyridines

Abstract

Tricoordinate phosphorus compounds react with a wide variety of double bonds through addition reactions. The dipolar and cyclic products formed are important intermediates in organophosphorus chemistry. We investigated the reactivity between phosphorus triamide 1 and nitrosoarenes and 2-acylpyridines. For sterically congested substrates, the formation of σ 5 , λ 5-phosphorus products is observed. DFT calculations indicate this product is formed through a concerted [4+1] mechanism. For less sterically congested substrates, products are observed arising from cleavage of the N=O or C=O bond with formation of a terminal P=O bond and aryl nitrene or carbene migration into a P-N bond of the phosphorus triamide core. DFT calculations are consistent with an initial [2+1] addition to phosphorus followed by formal carbene/nitrene migration in these cases.

Reactivity of a Strictly T‐Shaped Phosphine Ligated by an Acridane Derived NNN Pincer Ligand

“…Full perturbation towards a T‐shape (or C 2 v symmetry) results in a frontier‐orbital arrangement that is highly reminiscent of those found in tetrylenes, albeit with a significantly reduced directionality of the s‐type lone pair situated at the phosphorus center (Figure 1 , top). [ 11 , 12 , 13 , 14 ] Several geometrically constrained phosphines (and phosphenium cations, i. e. PR 2 + species) with ONO,[ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ] OON, [30] CCC,[ 31 , 32 , 33 ] NNN,[ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ] NPN,[ 50 , 51 ] SPS,[ 52 , 53 , 54 ] or NNS [55] donor sets have been reported, each showing unusual reactivity towards small molecules and unique spectroscopic and electronic pr...…”

Geometrically Deformed and Conformationally Rigid Phosphorus Trisamides Featuring an Unsymmetrical Backbone

“…[25] The resultant white crystalline solid was characterized by a doublet of doublets in the 31 P NMR spectrum at À 59.2 ppm, with coupling constants 1 J P-F of 936 and 749 Hz. The corresponding 19 F NMR spectrum contains two doublets of doublets for two chemically different fluorine nuclei at À 38.6 and À 46.1 ppm, with a 2 J F-F coupling constant of 57 Hz. These observations conclusively point to a trigonal bipyramidal geometry for complex 2 wherein one fluorine atom is at an equatorial site, the second at an axial site.…”

“…Abbenseth and Goicoechea reported the first site-specific hydrolytic bond cleavage using the nonsymmetric PSN2 platform -no oxidative addition was observed with this system. [18b] Other types of addition reactions have been disclosed as well, [19] and the unusual reactivity exhibited by these geometrically distorted P(III) centers has also been utilized for (catalytic) turnover in isolated cases. [20] Most of the more recent research in this area has utilized a relatively narrow set of ligand platforms.…”