Cyclic phosphinic amides, synthesis

The only comprehensive and readily-available surveys of thio- and seleno-phosphonic and -phosphinic acids appear to be those in the compilation by Kosolapoff and Maier which appeared during the 1970s, and those in the Houben-Weyl volumes. Some further information relevant to heterocyclic systems which possess endo- or exo-cyclic phosphorus-sulphur bonds has been surveyed by Mann Gefter has also provided a useful compilation of syntheses and data for unsaturated thiophosphonates and related compounds. As in the preceding chapters concerned with the synthesis of the various classes of phosphonic and phosphinic acids, literature surveys have been presented for individual compounds and the field, as a whole, is surveyed annually". In addition. Hall and Inch reviewed the mechanistic implications of changes in stereochemistry following displacement reactions at phosphorus in cyclic phosphorus(V) esters and amides, and in so doing discussed the reaction s of many such thiophosphoryl compounds. 

Cyclic and secondary amides, such as 2-pyrrolidinone, can be amidocarbony-lated only with formaldehyde (12). Lin and Knifton reported on the catalytic performance of various cobalt/ligand systems in the synthesis of iV-acetylglycine. Basic phosphines, such as PBus, allowed low pressure conditions (55 bar). The addition of Ph2SO or succinonitrile resulted in improved selectivity and facilitated the catalyst recovery (13-15). The addition of acid cocatalysts (plfa < 3 e.g., trifluoroacetic acid) allowed for low temperature conditions and the absence of hydrogen (16) (Scheme 3). 

Cyclic monomers that have been polymerized via ring-opening encompass a variety of structures, such as alkanes, alkenes, compounds containing heteroatoms in the ring oxygen [ethers, acetals, esters (lactones, lactides, and carbonates), and anhydrides], sulfur (polysulfur, sulfides and polysulfides), nitrogen [amines, amides (lactames), imides, N-carboxyanhydrides and 1,3-oxaza derivatives], phosphorus (phosphates, phosphonates, phosphites, phosphines and phosphazenes), or silicon (siloxanes, silaethers, carbosilanes and silanes). For the majority of these monomers, convenient polymerization conditions have been elaborated, that result in the controlled synthesis of the corresponding polymers [1-13]. 

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