1.3.2- Oxazaphosphorinane 2-oxides

Gluco- and galactopyranosides were reacted with phosphonic and phosphoric dihalides to provide dioxaphosphorinane oxides 73 and 74 as mixtures of the two phosphorus epimers, which were separated. A similar method was used to prepare oxathiaphosphorinanes 75 from the corresponding thiopy-ranoside. Dioxaphosphorinane sulfides 76 were prepared from phospho-nothioic dichlorides [RP(S)Cl2] or by oxidation of the corresponding P(III) precursor with sulfur. Finally, oxazaphosphorinane oxides and sulfides 77 were prepared similarly. ... 

Anilino-benzyl)-3-isopropyl-l,3,2-oxazaphosphorinan-2-oxid 39% Schmp. 154—155°... 

In gleicher Weise erhalt man 2-(4-Methoxy-anilino)- (44% Schmp. 180°) und 2-(4-Ethyl-anilino)-l,3,2-oxazaphosphorinan-2-oxid (37% Schmp. 177°). 

Oxazaphosphorinan 3-(2-Chlor-ethyi)-2-[(2-chlor-ethyl)-ethylamino]-4-hydroperoxid- -2-oxid E13/1, 575... 

Upon deboronation of 90 and 91 with DABCO, however, it was found that the free oxazaphosphorinanes are extremely sensitive to oxidation. Although Rh complexes could be detected by NMR, they are also very sensitive and give the corresponding oxides when exposed to air. 

The extreme sensitivity of oxazaphosphorinanes is surprising and shows that there can be discrepancies between basicity and oxygen sensitivity, pointing out that factors affecting oxidation rates in tricoordinated phosphorus compounds are still not clearly understood. 

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