A Safe and Efficient Route for the Preparation of Nitro-, Dinitro-, and Trinitrophenyl Chloroformates

A safe and simple method has been developed for synthesis of chloroformates derived from 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, 2,4,6-trinitrophenol, and pentafluorophenol, the yields being in the range of 72–96%. The method is based on a heterogeneous reaction of the substituted phenol with phosgene dissolved in dichloromethane catalyzed with solid anhydrous potassium carbonate. The synthesis of 2,4,6-trinitrophenyl chloroformate takes place only in the presence of a phase-transfer catalyst, in this case the easily recovered α,ω-dimethoxy poly(ethylene glycol) (PEG; M = 2 kDa). The only waste products of the suggested synthesis of the mentioned esters are sodium chloride and potassium chloride. The method markedly reduces the explosion risk connected with drying and handling of salts of mono-, di-, and trinitrophenols and is much more environmentally friendly than the currently used methods.

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An Efficient and Mild Preparation of Vinyl Diazo Carbonyl Compounds

The combination of (CF3CO)2O/Et3N is found to be a mild and efficient dehydration condition for β-hydroxy-α-diazo compounds.     

奥利司他的合成新路线

利用Mukaiyama-aldol反应、Noyori还原反应、Frater-Seebach烷基化反应构建奥利司他分子的3个关键手性中心,实现了奥利司他的全合成.     

Preparation and Structures of Dication Salts of Phenyl-Substituted TTF Vinylogues

Some TTF vinylogues 1 containing phenyl groups at the vinyl positions were synthesized. The redox properties were investigated by cyclic voltammograms, showing that they are strong electron donors and the Coulomb repulsion is decreased in the dication states. Some of the donors afforded their dication salts as single crystals by electrochemical oxidation or the reaction with CuCl₂. X-ray structure analysis has revealed that the dication molecules have structures with planar TTF vinylogue units and twisted phenyl groups. The crystal structures are unusual to avoid the steric interactions of the phenyl groups.     

Regioselective Addition of Dithiophosphinic Acids to Vinyl Sulfides and Selenides: An Efficient Route Toward Functional Dithiophosphinates

Earlier unknown S‐[1‐(organosulfanyl)ethyl]‐ and S‐[1‐(organoselenyl)ethyl] dithiophosphinates were synthesized in 85–97% yields by regioselective addition of dithiophosphinic acids to diverse vinyl sulfides and selenides under mild conditions (ambient temperature, Et₂O, 3 h).     

A Convenient Route for the Preparation of Aromatic Aldehydes

Though a variety of methods^2–5 are available for the synthesis of aldehydes, this area continues to attract attention^6,7 since aldehydes are important intermediates in synthetic organic chemistry. In this communication we present a new route for the synthesis of aromatic aldehydes.     

邻位锂化方法简便高效地合成邻羟基芳香醛: 在线红外在邻位锂化方法中的应用

利用DMF作亲电试剂通过对芳香羰基化合物邻位锂化的方法区域选择性地合成了一系列邻羟基芳香醛, 并且利用原位红外监测了反应过程, 证明了反应过程中间体六元锂络合物的存在.     

FeCl3-Mediated Reaction of Alkynols with Iodine: An Efficient and Convenient Synthetic Route to Vinyl Iodides

The FeCl₃-mediated reaction of alkynols with iodine resulted in intramolecular addition of hydroxyl to alkyne to produce a wide range of iodocycloenol ethers in good to excellent yields under mild reaction conditions. On the other hand, 1,2-diiodides were obtained in good yields when propargyl alcohol reacted with iodine in the same condition.

Reaction of Vinyl Aziridines with Arynes: Synthesis of Benzazepines and Branched Allyl Fluorides

We report the cycloaddition between vinyl aziridines and arynes. Depending on the reaction conditions and the choice of the aryne precursor, the aziridinium intermediate can be trapped through two distinct mechanistic pathways. The first one proceeds through a formal [5+2] cycloaddition to furnish valuable multi-substituted benzazepines. In the second pathway, the aziridinium is intercepted by a fluoride ion to afford allylic fluorides in good yields. Both reactions proceed stereospecifically and furnish enantiopure benzazepines and allylic fluorides.     

Efficient Electrocatalysis for the Preparation of (Hetero)aryl Chlorides and Vinyl Chloride with 1,2‐Dichloroethane

Although the application of 1,2‐dichloroethane (DCE) as a chlorinating reagent in organic synthesis with the concomitant release of vinyl chloride as a useful byproduct is a fantastic idea, it still presents a tremendous challenge and has not yet been achieved because of the harsh dehydrochlorination conditions and the sluggish C?H chlorination process. Here we report a bifunctional electrocatalysis strategy for the catalytic dehydrochlorination of DCE at the cathode simultaneously with anodic oxidative aromatic chlorination using the released HCl as the chloride source for the efficient synthesis of value‐added (hetero)aryl chlorides. The mildness and practicality of the protocol was further demonstrated by the efficient late‐stage chlorination of bioactive molecules.     

Efficient Route for the Synthesis of Highly Substituted Pyrroles

A mild and efficient synthesis of highly substituted pyrroles using the reaction of triphenylphosphine, α-diketone, ammonium acetate, and dialkyl acetylenedicarboxylates is described.     

A Versatile and Efficient Hydrosilylation Route to Functionalized Polyferrocenylsilanes

Summary: The synthesis of a series of polyferrocenylsilanes (PFSs) containing CC functionalities in the side‐group structure and their subsequent derivatization by hydrosilylation chemistry are described. Hydrosilylation is shown to be an effective postpolymerization functionalization method, particularly in the case of poly(ferrocenylmethylvinylsilane), which can be prepared by photolytic anionic ring‐opening polymerization of the corresponding ferrocenophane monomer.