Mercury silvering methods. The technique was also used in Asia, for example "tokin" plating in Edo-period Japan. Mercury silvering Mercury silvering or fire gilding is a silvering technique for applying a thin layer of precious metal such as silver or gold (mercury gilding) to a base metal object. The process was invented during the Middle Ages and is documented in Vannoccio Biringuccio's 1540 book "De la pirotechnia". An amalgam of mercury and the precious metal is prepared and applied to the object which is then heated, sometimes in oil, vaporizing most of the mercury. The technique is dangerous since mercury is highly
Pinacol coupling reaction rearrangement. A related reaction is the McMurry reaction, which uses titanium(III) chloride or titanium(IV) chloride in conjunction with a reducing agent for the formation of the metal-diol complex, and which takes place with an additional deoxygenation reaction step in order to provide an alkene product. Benzaldehyde may undergo the pinacol coupling photochemically, or with the use of catalytic vanadium(III) chloride and aluminium metal as the stoichiometric reductant. This heterogeneous reaction in water at room temperature yields 72% after 3 days with 56:44 dl:meso composition. In another system with benzaldehyde, Montmorillonite K-10 and zinc chloride in aqueous THF under ultrasound the