Scandium complexes alkoxides

Scandium complexes, 1059-1116 alkoxides, 1065 amides, 1062,1066 amine oxides, 1065 amines, 1060 amino acids, 1066 aromatic amines, 1061 arsenic compounds, 1065 2,2 -bipyridyl, 1061... 

The acetylacetonates are stable in air and readily soluble in organic solvents. From this standpoint, they have the advantage over the alkyls and other alkoxides, which, with the exception of the iron alkoxides, are not as easily soluble. They can be readily synthesized in the laboratory. Many are used extensively as catalysts and are readily available. They are also used in CVD in the deposition of metals such as iridium, scandium and rhenium and of compounds, such as the yttrium-barium-copper oxide complexes, used as superconductors. 1 1 PI Commercially available acetyl-acetonates are shown in Table 4.2. 

Synthetic strategies to alkoxide complexes have been covered in full by previous reviews [14]. The silylamide route proved to be an advantageous method of preparation, especially in the case of homoleptic derivatives [15]. The group (IIIA) elements - scandium, yttrium and lanthanum - are considered as lanthanides on the basis of their general chemical similarity to the true lanthanides. 

It is a commonplace to say that there has been explosive growth in the use of lanthanides in organic chemistry. For many years, the use of cerium(iv) compounds as oxidants was widespread, but more recently a whole range of other compounds have made their appearance. Thus samarium(ii) compounds are now routinely used as one-electron reducing agents and the use of trifluoromethanesulfonate ( triflate ) salts of scandium and the lanthanides as water-soluble Lewis acid catalysts is widespread. Beta-diketonate complexes and alkoxides have also come into use there are even applications of mischmetal in organic synthesis. 

Scandium enolate chemistry is quite limited. The complex (nacnac)Sc(NHAr)(HBEt3) where nacnac = 21 and Ar = 2,6-(/-Pr2)2C6H3) reacts with THF to form the enolate (nacnac)Sc(NHAr)OCH=CH2 while diethyl ether forms the related alkoxide (nac-nac)Sc(NHAr)OEt. This suggests considerable stabilization due to the Sc—O bond. After all, ring opening of THE is energetically unfavorable (THE EtOVi A// > 40 kJ mor ). 

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