Biphilic Reactions with Carbonyl Compounds

Reagents i, EtPCh, heat ii, EtOH-base iii, Et2PCl iv, ROH v, AC2O 

Several papers this year have been devoted to the effect of acids, notably acetic acid, on reactions between carbonyl compounds and chlorophosphines. Thus dichlorophosphines react with cyclic ketones to give the phosphinic chlorides (40), but in the presence of acetic acid the products are a-hydroxyalkyl derivatives, such as (41). When phosphorus trichloride and acetic acid are added to 1,5-diketones, bicyclic phosphonates (42) are formed the authors suggest that the reaction is 

Reactions of halogenophosphines with ajS-unsaturated carbonyl compounds include addition to a-bromoacrylic acid (43) and additions to the ketones (44), the 

When chlorodiphenylphosphine (2) and benzaldehyde react in the presence of acetic acid, a-hydroxybenzyldiphenylphosphine oxide (47) is formed rapidly. Thereafter this is slowly converted into a mixture of the corresponding acetate and the ether derivative (48) Further aspects of these phosphine oxides are discussed in Chapter 4. 

Miller, in Organophosphorus Chemistry , ed. S. Trippett, (Specialist Periodical Reports), The Chemical Society, London, 1977, Vol. 8, p. 55. 

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Biphilic Reactions with Carbonyl Compounds.—The dichlorophosphine (34) undergoes a standard chloromethylation when heated with paraformaldehyde, and a good yield of the phosphinic chloride (37) is obtained. At temperatures below 100 °C, the ester (38) is isolated, and the authors discuss, somewhat speculatively, the mechanism of the reaction see Scheme 3. 

Biphilic Reactions with Dienes or Carbonyl Compounds. Stereochemical details have appeared of the reactions between substituted 1,3-dienes and halogenophosphines, such as dichloromethylphosphine (21a) and dibromo-phenylphosphine (21b). In general, both cis- and /ra/i5-adducts are formed, and they are not interconvertible via quinquecovalent intermediates. The conversion of these adducts to A -phospholens or to A -phospholen-l-oxides produces cis-trans mixtures. 

Biphilic Reactions with Dienes and with Unsaturated Carbonyl Compounds. The Diels-Alder reactions of the aj8-unsaturated lactone (40) have been described. The lactone is prepared by treatment of chloro-methyldichlorophosphine (41) with propiolic acid and then hot acetic... 

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