IV- amides

Table IV. Amide Content of Kerogen and Trona Acids...

Somewhat related to these subvalent Group IV amides is the recent discovery of the novel... 

Compounds of type [Cp2LnNH2]2 were obtained by simple metathesis reaction or by thermal decomposition (200-250 °C) of complexes Cp3Ln(NH3) according to Eq. (3) [4,62]. Both the ammonia (150-160 °C, for the smaller lanthanides) and the heteroleptic amide complexes (230 °C) can be sublimed under high vacuum. The Ce(IV) amide derivatives Cp3CeNH2 and Ind2Ce(NH2)2 were also discussed as metathesis products. 

While the investigation of Ce(IV) organyl [152] and alkoxide compounds [153] has attracted some attention, Ce(IV) amide chemistry was investigated in detail... 

Recently Liu and coworkers used (porphyrin)iron(III) chloride complex 96 to promote 1,5-hydrogen transfer/SHi reactions of aryl azides 95, which provided indolines or tetrahydroquinolines 97 in 72-82% yield (Fig. 24) [148]. The reaction starts probably with the formation of iron nitrenoids 95A from 95. These diradicaloids undergo a 1,5- or 1,6-hydrogen transfer from the benzylic position of the ortho-side chain. The resulting benzylic radicals 95B react subsequently with the iron(IV) amide unit in an Sni reaction, which liberates the products 97 and regenerates the catalyst. /V,/V-Dialkyl-w// o-azidobenzamides reacted similarly in 63-83% yield. For hydroxy- or methoxy-substituted indolines 97 (R2=OH or OMe) elimination of water or methanol occurred from the initial products 97 under the reaction conditions giving indoles 98 in 74—78% yield. 

Such transformations may be described as aminometallations of the substrate Z, a generic term derived from aminoboration , and they have been extensively reviewed, especially for tin(IV) amides, such as Me3SnNMe2. ... 

Scheme 22 Synthesis of the heteroleptic Ce(IV) amide complex 35. Reproduced from [77] with permission of American Chemical Society...

III) ester and carboxylic acid (Iv) amide (v) phenol, alcohol, amino (vl) halogen. 

A suitable entry into titanium and zirconium complex chemistry is the use of group IV amides and alkoxides. For example, when Ti(OEt)4 reacted with 2 equiv. of (roc)-2 in heptane, the titanium bis(disiloxide) 3 could be isolated in 91 % yield as a yellow microcrystalline material. Tbe results of the X-ray analysis (Fig. 1) of 3 confirm the expected extensive shielding of the titanium atom by the two sterically demanding disiloxide ligands. The geometry around the titanium atom is described best as distorted tetrahedral, with an 02-Til-02 chelate angle of 99° and an 02-T11-01 angle of 115.5°. 

The various thorium(IV) amides and imides are readily hydrolysed [1 to 3]. 

G. Chandra, M. F. Lappert, Amido-derivatives of metals and metalloids. Part VI. reactions of titanium(iv), zirconium(iv), and hafnium(iv) amides with protic compounds. J. Chem. Soc. A, 1968 1940. 

Buchwald and co-workers reported that the combination of air stable Cul (instead of the air sensitive CuOTf) and racemic trans-1,2-cyclohexanediamine (ligand la), in the presence of K3PO4, K2CO3, CS2CO3, or f-BuONa comprises an extremely efficient and general catalyst for the iV-amidation of aryl and heteroaryl halides (eq 9) and the Ai-arylation of a number of heterocycles (eq 10). This approach tolerates functional groups such as primary or secondary amides, free OH or NH on the aryl halides, which were problematic with the Pd-catalyzed amination methodology. 

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