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The reaction of 1,3-diphenyl-2-(phenylimino)-3-(ylidenemethyl-acetate)-1-propanone (5) with trisdialkylaminophosphines (6a,b) in refluxing toluene afforded the new oxazaphospholene products (7a–b). On the other hand, the cyclic azaphospholene adducts 8a–b were isolated from the reaction of 5 with 6a,b without solvent. Trialkyl phosphites 1b–c react with compound 5 to give the respective dialkyl phosphate products (9a,b). Moreover, trisdialkylaminophosphines (6a,b) react with 2a and 2b to give the dipolar adducts 10a,b and the phosphonate products 11a,b, respectively. Possible reaction mechanisms are considered, and the structural assignments are based on compatible analytical and spectroscopic results. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:511–517, 2001

N-Phenyliminophosphorane (1) reacts with 9,10-phenanthrenequinone (2a) to give the new products 2-phenylphenanthro[9,10-d][1,3,2]dioxazole (4a) and (10Z)-10-(phenylimino)-9(10H) phenanthrenone (4b). The reaction of 1 with 1,2-naphthoquinone (2b) afforded both the dioxazole derivative 5a and the known 2-anilino-naphthoquinone-1,4-anil (5b). On the other hand, 2,6-di-tert-butyl-2,3-diphenyl-2,3-dihydro-1,2,3-benzoxadiazole (6) was obtained from the reaction of (2c) with phosphinimine (1). Application of reagent 1 on 2d and 2e renders (6E)-2,3,4,5-tetrahalogeno-6-(phenylimino)-2,4-cyclohexadien-1-one 7a and 7b, respectively. Moreover, p-quinones (3a–3c) react with phosphinimine (1) to yield products 8, 9 and 10, respectively. Mechanisms accounting for the formation of the new products are discussed and the probable structures of the products are presented based on analytical and spectroscopic data.

Methylenetriphenylphosphoranes (IIa, b) react with 1,4-naphthoquinonemonobenzenesulfonimine (I) yielding the new azapropane adduct IIIa together with the dimeric adducts IIIb, IIIc, and IIId. Structures of the new products were established by analytical and spectroscopic (IR, 1H NMR, 31P NMR, 13C NMR, and MS) results. A mechanism is proposed to explain the formation of compounds III.

Tris(dimethylamino)phosphine (IIIa) and/or Bis-dimethylaminophenyl-phosphine (IIIb) react with 9,10-dihydro(9-dicyanomethylene)phenanthrene-10-one (Ib) to produce 1:1 adducts which have the aminophosphonium dipolar ion structure (V) in the crystalline state and in solutions. The 1:1 adduct isolated from the reaction of IIIb with 9,10-phenanthrenequinonemonoimine (Ic) has a similar dipolar structure (XII) in the crystalline state. Solutions of the latter contained the same molecular species (XII) in equilibrium with a cyclic aminophospholene species (XIII). Only decomposition products could be observed from the reaction of IIIa with Ic. The products in this case were the phosphoroamidate (X), 9,10-phenanthrenequinone (Ia) and phenanthroxazine XI. A mechanism is proposed to explain the formation of these compounds.

Depending upon the type of Wittig reagents, naphthalenone 1 reacts with reagents 3a and 3b to give adducts 4 and 5 respectively. Reaction of 1 with phosphacumulene 6 gives the phosphorane 7. On the other hand, naphthalenone 2 reacts with 3a and 3b to give adducts 8 and 9. The identity of the new compounds is established from analytical and spectroscopic evidences.

The reaction of carbmethoxymethylene (1a)-, carbethoxymethylene (1b)-, acetylmethylene (1c)-, and benzoylmethylene (1d)-triphenylphosphoranes with N,N′-2,5-cyclohexadiene-1,4-diylidenebis (methanesulfonamide) (IIa) and its 2-chloro-derivatives IIb afforded the new ylid-phosphoranes IIIa-g via 1,2-addition reaction. Structural reasoning for compounds 111 was based on compatible analytical and spectral data (IR, 1H NMR, 31P NMR, 13C NMR, and MS). The mechanism that accounts for formation of adducts III is discussed.

The reaction of methylenetriphenylphosphoranes (1) with N,N′-3,5-cyclohexadiene-1,2-diylidenebis [benzamide] (2) afforded new ylid-phosphoranes of type 3. The mechanism that accounts for formation of adducts 3 is discussed. Structural reasoning for compounds 3 was based on compatible analytical, chemical and spectroscopic results.

Methylenetriphenylphosphoranes (2a-b) react with N,N′-2,5-cyclohexadiene-1,4-diylidenebis [benzamide] (1) yielding the new ylid-phosphorane adducts 3a and 3b, respectively. Quinoneimine 1 is reduced mainly to p, -Phenylenedibenzamide (7) when treated with ylid 2c under similar conditions. Structures of the new products were established by analytical and Spectroscopic (IR, 1H NMR, 31P NMR, 13C NMR, and MS) results. A mechanism is proposed to explain the formation of compounds 3.

The reaction of 2-benzylidene-1,3-diphenylpropanetrione (1a) with phosphorus ylides 2a–c afforded the new phosphonium ylides 4a–c. Trialkyl phosphites 3a–c react with 1a to give the respective dialkyl phosphonate products 5a–c. On the other hand, the olefinic compounds 6 and 7 were isolated from the reaction of 1b with Wittig reagents 2. Moreover, trialkyl phosphites reacted with 1b to give products 8a–c. Possible reaction mechanisms are considered, and the structural assignments are based on analytical and spectroscopic evidence. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:57–64, 2000

Lawesson's reagent (1a) reacts with pyrogallol (2) to give 1,3,2-benzodioxaphospholane-2-sulfide (3) and with 1,8,9-trihydroxyanthracene to give 13. The structures of the products have been established either chemically, using methanolysis and methylation, or spectroscopically. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 25–30, 1999

Simple, rapid and highly sensitive iodimetric amplification methods are described for the micro- and submicro-determination of antimony(III) in antibilharzial compounds. The methods are based on oxidation of the sample with an excess of periodate in acetate buffered medium, masking of the unreacted periodate with molybdate, and finally, iodimetric titration of the iodate that is released. Specific reactions have been found to occur for the four different compounds analysed owing to the presence, in the same molecule, of one or two antimony(III) and α-diol functions, both of which are oxidised quantitatively and simultaneously by periodate. Thus 3-, 9-, 15- and 18-fold amplification is achieved with triphenylstibine, tartar emetic, stibophen and diantimony piperazine tartrate, respectively. The total mean recovery is 99·49 per cent.