Improved Methodology for the Preparation of Chiral Amines

longest-lived radioisotope Yb-169, t1/2 32.03 days; shortest-lived radioisotope Yb-154, 0.40
second.
5.1.1.2. Ytterbium Discovery:
Ytterbium was discovered in 1878 by J. C. G. de Marignac. The element got its name from
the Swedish village Ytterby where this rare earth first was discovered. In 1907, Urbain
separated ytterbia into two components, neoytterbia (oxides of ytterbium) and lutecia
(lutecium). The first preparation of metallic ytterbium was achieved by Klemm and Bommer
through reduction with potassium metal resulting in an impure ytterbium metal (mixed with
potassium chloride). Daane, Dennison, and Spedding were the first to prepare the pure metal
in 1953 in gram quantities. Abundance of ytterbium in the earth’s crust is estimated to be 3.2
mg/kg. Up till now the metal had showed very little applications on the commercial level. In
elemental form it can be used as a laser source, a portable x-ray source, and as a dopant in
garnets. When added to stainless steel, it improves grain refinement, strength, and other
properties. Some other applications, particularly used as oxides mixed with other rare earths,
include carbon rods for industrial lighting, in insulated capacitor and in glass industry. Its
radioactive isoptope is used in detection of metal perfection.
5.1.1.3. Ytterbium Reactions:
Ytterbium metal reacts with oxygen above 200°C forming two oxides, the monoxide, YbO,
and more stable sesquioxide, Yb 2 O 3 . The metal dissolves in dilute and concentrated mineral
acids. At ordinary temperatures, ytterbium, similar to other rare earth metals, is corroded
slowly by caustic alkalies, ammonium hydroxide, and sodium nitrate solutions. The metal
dissolves in liquid ammonia forming a deep blue solution. It can react slowly with halogens
at room temperature but progress rapidly above 200°C forming ytterbium trihalides. All the
trihalides; namely, the YbCl 3 , YbBr 3 , and YbI 3 with the exception of trifluoride, YbF 3 , are
hygroscopic and soluble in water. Ytterbium forms many binary, metalloid, and intermetallic
compounds with a number of elements when heated at elevated temperatures. It can form salt
with organic acid triflic or acetic acid. These salts and the salts with halogens are used as
Lewis acids in different organic transformations. [6]
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