C–H activation of the methyl group of toluene and related ArCH3 derivatives by 2,3-dichloro-4,5-dicyano-1,4-benzoquinone (DDQ) gives insertion products, ArCH2O[C6Cl2(CN)2]OH via a rate-determining hydride abstraction by DDQ. The resulting benzylic ether can undergo reactions with phosphines to give benzylic phosphonium salts (Wittig reagents) and with phosphites to give phosphonate esters (Horn...

ABSTRACT The phosphonate-substituted zirconium oxo clusters Zr6O2(OBu)12(O3PPh)4 and Zr7O2(OiPr)12(O3PCH2CH2CH2Br)6, with octahedrally coordinated Zr atoms, were synthesized by reaction of zirconium alkoxides with phosphonic acid bis(trimethylsilyl) esters. The basic structural motif are Zr3O(µ2-OR)3(OR)3 units which are connected in different ways. GRAPHICAL ABSTRACT

We describe a four-step sequence for the synthesis of complex 2-hydroxy-1-naphthoic acids involving Z-selective olefination of benzaldehyde derivatives with a novel dioxolenone-containing phenyl phosphonate reagent, followed by dioxolenone cleavage with alkaline trifluoroethanol and oxidative cyclization (Mn(OAc)(3)) of the resultant trifluoroethyl beta-keto esters. [reaction: see text]

Z. Naturforsch. 58b, 106 – 110 (2003); received September 18, 2002 Benzyloxyureas (4) have been prepared by reactions of diethyl 3-benzyloxyamino-propyl-phosphonate (3) with isocyanates, potassium cyanate or 1,1’-carbonyldiimidazole / methylamine. Conversion of phosphonic esters 4 into phosphonic acids 6 by means of bromotrimethylsilane and catalytic hydrogenation of 4, 6 afforded the target co...

A new series of ether lipid esters of cidofovir (CDV) were evaluated against vaccinia and cowpox viruses. Activity was dependent on number of atoms in the alkyl or alkoxyalkyl chain, the linker moiety, and the presence of a double bond in the alkoxyalkyl chains linked to the phosphonate moiety of CDV.

Reaction of dialkyl acetylenedicarboxylates 1a-c andpyrrole derivatives 2a-e in the presence of triphenylphosphite (TPP) was investigated and the effect of the pyrrole substitution was established. Diastereoselectivity is observed with pyrroles, 2a,b, yieldingphosphonate ester derivatives 3a-f and 4,and their relative configuration is determined by 1H/13C and 31</...

Selective lactone form ation from hydroxy esters can be obtained with m icroporous glass catalysts. By a sol-gel polycocondensation o f TEO S and a cyclic phosphonate an im printed m icroporous silica catalyst was prepared. The imprint m olecule selected is a transition state analogue for the lactone form ation from hydroxy esters. A lthough selective yand ^-lactone form ation from the respecti...

Traditional P NMR or MRI measurements suffer from low sensitivity relative to H detection and consequently require longer scan times. We show here that hyperpolarization of 31 P nuclei through reversible interactions with parahydrogen can deliver substantial signal enhancements in a range of regioisomeric phosphonate esters containing a heteroaromatic motif which were synthesized in order to id...

Traditional (31)P NMR or MRI measurements suffer from low sensitivity relative to (1)H detection and consequently require longer scan times. We show here that hyperpolarization of (31)P nuclei through reversible interactions with parahydrogen can deliver substantial signal enhancements in a range of regioisomeric phosphonate esters containing a heteroaromatic motif which were synthesized in ord...