A practical and general synthesis of unsymmetrical terphenyls

A synthetic procedure was developed that enables sequential chemoselective Suzuki-Miyaura cross-coupling of chlorobromobenzene with arylboronic acids. The first coupling is achieved at room temperature using a ligandless palladium catalyst. The chlorobiaryl product can then be subjected directly to the second coupling, facilitated by the SPhos ligand. Using this methodology, parallel synthesis of 32 unsymmetrical o-, m-, and p-terphenyl compounds was accomplished in good to excellent overall yields.     

Reactions of chlorination with tert‐butyl hypochlorite (TBuOCl)

The chlorination reactions of nitrogenous organic compounds (2,2,2‐trifluoroethylamine, benzylamine, glycine, and dimethylamine) by tert‐butyl hypochlorite (^tBuOCl) were studied at 25 °C, ionic strength 0.5 M and under isolation conditions. The kinetic results obtained in the formation processes of the corresponding N‐chloramines in acid medium (pH = 5–7) are summarized in this paper. Kinetic studies showed a first order with respect to ^tBuOCl concentration. The chlorination reactions involving benzylamine, glycine and dimethylamine were all first order with respect to nitrogenous compound concentration and approximately ?1 order with respect to proton concentration. The reaction with 2,2,2‐trifluoroethylamine was more complex, and the order of reaction with respect to the amine varied with pH. Copyright © 2014 John Wiley & Sons, Ltd.