- A systematic study on the activation of simple polyethers by MoCl 5 and WCl6
-
MoCl5, 1a, and WCl6, 1b, activate 1,3-dioxolane at room temperature in chlorinated solvents: the compound [MoOCl 3{OC(H)OCH2CH2Cl}]2, 2, has been isolated from MoCl5/dioxolane. The mixed oxo-chloro species WOCl 4, 1c, reacts with 1,3-dioxolane, selectively giving the coordination adduct WOCl4(κ1-C3H6O 2), 3. Dimethoxymethane, CH2(OMe)2, undergoes activation including C-H bond cleavage when reacted with 1a to give the molybdenum complexes [MoOCl3{OC(H)OMe}]2, 4, and Mo 2Cl5(OMe)5, 5. The reactions of 1b with CH 2(OR)2 (R = Me, Et) proceed via O-abstraction with formation of the oxo-derivatives WOCl4[O(R)CH2Cl] (R = Me, 6a; R = Et, 6b) in admixture with equimolar amounts of RCl. The reactions of 1a,b with CMe2(OMe)2 lead to mesityl oxide, MeC(O)CHC(Me)2. A series of simple diethers of general formula ROCH2(CHR′)OR′′ are activated by 1a,b in CDCl 3, usually via cleavage of C-O bonds at high temperature. The complex WCl5(OCH2CH2OMe), 7, has been detected in solution as an intermediate species in the course of the degradation of 1,2-dimethoxyethane (dme) by 1b. The activation of CH(OMe)3 by 1 is limited to C-O bonds and selectively gives methyl chloride and methylformate, which has been found coordinated in WOCl4[OC(H)OMe], 8. The organic fragments produced in the reactions have been detected by GC-MS and NMR analyses, upon hydrolysis of the reaction mixtures. Compounds 2 and 5, which have had their molecular structures ascertained by X-ray diffraction, represent rare examples of crystallographically-characterized dinuclear Mo(v) species containing both halides and oxygen ligands.
- Dolci, Sara,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
-
experimental part
p. 5367 - 5376
(2010/08/04)
-
- Synthesis of acyclic nucleoside phosphonates as antiviral compounds
-
Reaction of 6-chloropyrimidines with diethyl [(2-aminoethoxy)methyl]phosphonate allows for a ready access to acyclic nucleoside phosphonates. A series of 5-substituted pyrimidines bearing a phosphonate side chain at position 6 were synthesized and tested against herpes simplex viruses (HSV-1 and HSV-2) and human immunodeficiency virus (HIV-1). Some compounds showed weak antiviral activity against HSV-1.
- Wormstadt,Brinckmann,Gutschow,Eger
-
p. 1187 - 1191
(2007/10/03)
-
