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
Koenigs–Knorr reaction can be performed with alternative promoters such as various heavy metal salts including mercuric bromide/mercuric oxide, mercuric cyanide and silver triflate. When mercury salts are used, the reaction is normally called the Helferich method. Other glycosidation methods are Fischer glycosidation, use of glycosyl acetates, thioglycosides, glycosyl trichloroacetimidates, glycosyl fluorides or n-pentenyl glycosides as glycosyl donors, or intramolecular aglycon delivery. Koenigs–Knorr reaction The Koenigs–Knorr reaction in organic chemistry is the substitution reaction of a glycosyl halide with an alcohol to give a glycoside. It is one of the oldest and simplest glycosylation reactions. It is named after Wilhelm Koenigs (1851–1906), student