A New Protocol for O-Methylation of Phenolic Compounds with Trimethyl Phosphite or Trimethyl Phosphate Under Solvent-Free Condition and Microwave Irradiation

A simple method for the preparation of industrially important alkyl aryl ethers is reported. Several phenolic compounds such as phenols, naphthols, and hydroxy coumarins were O-methylated with trimethyl phosphite or trimethyl phosphate under microwave irradiation and solvent-free condition in almost quantitative yields. Reaction of 2-naphthol with trimethyl phosphate gave mixture of 2-methoxynaphthalene and 1-methyl-2-methoxynaphthalene while the reaction with trimethyl phosphite gave mostly 2-methoxynaphthalene. This method is highly efficient for the methylating of phenolic compounds with very easy experimental procedure and environmental friendly conditions.     

Addition Reaction Between Trimethyl Phosphite and Dibenzoylacetylene in the Presence of SH- or NH-Acids

The reactive 1:1 intermediate produced in the addition reaction between trimethyl-phosphite and dibenzoylacetylene was trapped by SH- or NH-acids such as 4-nitroimidazole, 4-methyl-5-nitroimidazole, succinimide, or mercaptoacetic acid to produce 2-substituted 1,4-diphenylbutane-1,4-diones.     

NMR Characterization of Substituted Aromatic Poly (Ether Sulofone)s

Abstract

The synthesis of a variety of substituted bisphenol A polysulfones, including nitro, amino, aminomethyl, ethyl, and methyl derivatives, is described. Nuclear magnetic resonance (NMR) (both proton and carbon, and several 2-D experiments) data confirm conclusions on the substitution site based on arguments on inductive effects in the phenyl rings. The proton ortho to the oxygen in the bisphenol A (BPA) residue is replaced in electrophilic substitution reactions. The degree of substitution was also calculated from the NMR results. The ethyl and methyl derivatives were expected, from the starting reactants, to each have a BPA ring substituted. The NMR data showed that, on the average, this is true. The nitro derivative also has substitution in every BPA ring, while the amino and aminomethyl derivatives have only intermittent BPA rings substituted. Measured degrees of substitution (DS) varied from 0.11 to 2.25.     

Simple and Advantageneous Stereoselective Synthesis of (Z)-Allyl Phosphonates Starting from Baylis–Hillman Adducts

Baylis–Hillman adducts 3-hydroxyl-2-methylene alkanoates have been converted in one pot into the corresponding (Z)-allyl phosphonates by treatment with FeCl₃ and trialkyl phosphites in toluene under reflux. The products are formed in excellent yields (88–98%) within 1–1.5 h. The process is highly convenient and efficient, cost-effective, and remarkably stereoselective.     

ZrOCl2·8H2O: An Efficient Catalyst for One-Pot Synthesis of α-Amino Phosphonates Under Solvent-Free Conditions

A highly efficient protocol has been developed for the three-component reaction of an amine, an aldehyde, and diethyl phopshite catalyzed by ZrOCl₂·8H₂O, an environmentally friendly catalyst, at ambient temperature. The catalyst exhibited remarkable activity and tolerated a wide variety of functional groups, providing the desired amino phosphonates in excellent yields under solvent-free conditions. Alternatively, the reaction rate can be significantly enhanced by carrying out the reaction in a monomode microwave reactor as a promoter.     

2-亚磷酸二乙酯基杂环烯酮缩胺类化合物的合成

用廉价易得原料Mn(OAc)2-KMnO4体系代替昂贵的Mn(OAc)3催化二甲缩硫醚(1)与亚磷酸二乙酯反应获得结构新颖的2-亚磷酸二乙酯基缩硫醚化合物2a～2d.然后,化合物2a～2d与二胺类化合物3反应以较高产率合成了一系列2-亚磷酸二乙酯基杂环烯酮缩胺(4).     

Highly effective and enantioselective Phospho-Aldol reaction of diphenyl phosphite with N-alkylated isatins catalyzed by quinine

Cinchona alkaloids were first successfully reported to promote enantioselective Phospho-Aldol reaction of diphenyl phosphite to a variety of N-alkylated isatin derivatives in good to excellent yields (up to 99%) and moderate to good enantioselectivities (up to 73% ee) almost in no time.     

One-pot three-component Kabachnik-Fields synthesis of α-aminophosphonates using H-beta zeolite catalyst

One-pot three-component Kabachnik-Fields synthesis of α-aminophosphonates with high yields from the reaction between carbonyl compound, primary amine, and substituted phosphite can be carried out in a short period, using H-beta zeolite as a reusable catalyst.     

A Novel Synthesis of Alkylamino Substituted Methylenediphosphonates Using Bis(trichloromethyl) Carbonate and RCONR1R2

An efficient, economical and easy method for the synthesis of dimethylaminomethylenediphosphonates using bis(trichloromethyl) carbonate and RCONR1R2 has been developed, which proceeded under relatively mild conditions.