Phosphites, trialkyl reaction with acyl halides

Sulfonic esters are most frequently prepared by treatment of the corresponding halides with alcohols in the presence of a base. The method is much used for the conversion of alcohols to tosylates, brosylates, and similar sulfonic esters. Both R and R may be alkyl or aryl. The base is often pyridine, which functions as a nucleophilic catalyst, as in the similar alcoholysis of carboxylic acyl halides (10-21). Primary alcohols react the most rapidly, and it is often possible to sulfonate selectively a primary OH group in a molecule that also contains secondary or tertiary OH groups. The reaction with sulfonamides has been much less frequently used and is limited to N,N-disubstituted sulfonamides that is, R" may not be hydrogen. However, within these limits it is a useful reaction. The nucleophile in this case is actually R 0 . However, R" may be hydrogen (as well as alkyl) if the nucleophile is a phenol, so that the product is RS020Ar. Acidic catalysts are used in this case. Sulfonic acids have been converted directly to sulfonates by treatment with triethyl or trimethyl orthoformate HC(OR)3, without catalyst or solvent and with a trialkyl phosphite P(OR)3. ... 

Reaction of an acyl halide with a trialkyl phosphite catalyzed by Ni(II)... 

Although those Michaelis-Arbuzov reactions which involve acyl halides and phospho-rus(III) esters are yet a further route to phosphorus-carbon bond formation and will be discussed later in Section VI, the use of halogenated acyl halides has led to some unusual results which, conveniently, can be summarized here. The products obtained from reactions between trialkyl phosphites and perfluoroacyl chlorides contain both phosphonate and phosphate moieties and are structurally dependent on reaction temperature. The initial product (Scheme 4) is thought to be the ylide 66. In an ethereal solvent at low temperature, decomposition of the ylide yields [l-(dialkoxyphosphinoyl)oxy-l/f-perfluo-roalkyl]phosphonates (67) exclusively, but at -20 °C and above, and in the absence of a solvent, the products consist of (Z)-[l-(dialkoxyphosphinoyl)oxyperfluoroalkene]phos-phonates (68) . The treatment of the compounds 67 with Ida yields 68, and the action of BuLi-CuI on 68 results in loss of the phosphate moiety to give the esters 69 The structural isomers 70 of the compounds 68 have been obtained as illustrated in equation... 

---