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The synthesis of eight chloroformates using bis(trichloromethyl)carbonate(BTC) is reported. It has been found that the yields by this BTC method are improved over the earlier phosgene method, and sodium hydroxide is better than pyridine as catalyst for the preparation of phenyl chloroformate.

The novel coupling reaction of sodium tetraphenylborate with hypervalent iodonium salts was achieved in acidic water, providing an efficient and rapid method for the formation of carboncarbon bonds in excellent yield.The Suzuki reaction is one of the most versatile and utilized reactions for the selective construction of carboncarbon bonds, in particular for the formation of biaryls. 1 These coupling reactions are utilized extensively in the synthesis of pharmaceuticals, herbicides, and natural products as well as conducting polymers and liquid crystalline materials because they use nontoxic readily available organoboranes, yield easily removable nontoxic byproducts, and tolerate many functional groups. However, the use of heavy metals as catalysts leads to the generation of waste, which can have a number of problems associated with it, thus the eradication of the catalyst from the Suzuki reaction offers significant advantages. Recently, Leadbeater and Marco reported the first catalyst-free Suzuki coupling reaction under microwave irradiation. 2 They investigated the coupling of aryl halides with arylboronic acids, which afforded biaryls in excellent yields when aryl bromides were reacted with arylboronic acids in water under microwave heating at 150 °C for five minutes. However, due to the development of pressure and the need for specialized sealed vessels this method is not suitable for organic reactions carried out at atmospheric pressure and it is also difficult to apply on an industrial scale. In order to extend the scope of the catalyst-free Suzuki reaction the development of mild, efficient, and environmentally more benign metal-catalyst-free conditions are required.During the past few years the chemistry of hypervalent iodine compounds has experienced an unprecedented growth. 3 As powerful electrophilic reagents, hypervalent iodine compounds, in particular, hypervalent iodonium salts have found synthetic application due to their high reactivity toward various nucleophiles, their ready availability, and their nontoxic properties. They have been widely used in the Suzuki reaction to replace aryl halides or triflates affording products in excellent yield under mild reaction conditions. 4 As part of a program to investigate the catalyst-free Suzuki reaction, we explored the coupling reaction of sodium tetraphenylborate with iodonium salts in acidic water. In this paper, we would like to report a novel and efficient coupling reaction of sodium tetraphenylborate with iodonium salts in acidic water. This method was successfully applied to the synthesis of biaryls, and to the best of our knowledge, the metal-catalyst-free Suzuki-type coupling reaction of sodium tetraphenylborate with iodonium salts in acidic water has not been reported.Initially, we investigated the catalyst-free coupling reaction of phenylboronic acid with diphenyliodonium chloride in water by traditional heating methods. We found that the coupling was difficult to effect and the desired biphenyl was not obtained either in the presence or absenc...

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