Tris benzyl

Fig. 6. Planar and pyramidal skeleton of tri(phenylsilyl)amine and tri(benzyl)amine [22]...

Considerably less is known about single ring complexes of the type Cp AnR3. According to Marks, thermal stability is a sensitive function of both the metal and the alkyl group. The synthetic approach of equation (63) has yielded only a few isolable compounds despite considerable effort. The X-ray stractures of the tris-benzyl compounds Cp Th(CH2C6H5)3 and Cp U(CH2C6H5)3 revealed multihapto metal-benzyl interactions. The latter may explain the stability of... 

In the alpha compound the benzyl group replaces the hydroxyl hydrogen of hydroxyl amine while in the beta compound it replaces one of the amino hydrogens. There are also known two isomeric di-benzyl hydroxyl amines and one tri-benzyl hydroxyl amine. 

The anomeric selectivity observed in the synthesis of glucosides (including disaccharides) by reaction of 1-0-metallated 2,3, -tri- -benzyl-D-glucose compounds with alkyl triflates is dependent upon the substituent at 0-6. Good g-selectivity was observed for the 6-benzyl ether, while for the monomethoxytrltyl derivatives, the a 6 ratio was dependent upon the triflate employed.The 0-xylosyl serine derivative (9) has been made using the trlchloro-... 

To a solution 0.46 g 2-[(lS,4S,5R,6S)-4,5,6-tris(benzyloxy)cyclohex-2-enyloxy]-acetaldehyde (1 mmol) in 5 mL anhydrous toluene was added a solution of 0.12 g N-benzyl-hydroxylamine (1.1 mmol, prepared from the hydrochloride acid with 0.1 mL triethylamine) in 2 mL anhydrous dichloromethane. The reaction mixture was stirred at 20°C for 2 h. Removal of the solvents under reduced pressure furnished a residue, which was chromatographed to give 0.4 g (2fl5,4aS,5S,6S,7R,7aR,7 R)-2-benzyl-5,6,7-tris(benzyl-oxy)octa-hydro-2H-furo[4,3,2-c,d][l,2]benzisoxazole as a colorless wax, in a yield of 70%. Rf = 0.45 (toluene/ethyl acetate, 5 1). a] = 86.14 (c = 1.0, CHCI3). 

The unsaturated lactones (13) are obtainable directly from the corresponding 2,3-unsaturated ethyl a-glycosides by treatment with pyridinium chlorochromate in the presence of acid resin or with Jones reagent.Treatment of 2,4,6-tri- -benzyl-3- -tosyl-D-... 

Both anomers of tri- -benzyl-D-ribofuranosyl fluoride with 2-trimethylsilyloxypropene and boron trifluoride gave a very high yield of the acetone compound and both anomers of the... 

The same trans structure was observed by Dolgophosk and his group (15) by using tris(benzyl)neodymium as catalyst for the polymerization of butadiene and isoprene. 

Most of the above mentioned results and in particular the differences among 4f and d elements still must be explained. If we look at the molarities involved in the polymerization reaction we obtain no further information. Different reaction orders are reported in the literature while a first order is found on both butadiene (25, 27) and isoprene (25, 37, 38) homopolymerization, first (25) and second (33) order (with respect to total monomer concentration) are indicated in the case of copolymerization. As for the catalyst, the reaction order appears to range between 0.5, as for the tris(benzyl)-neodymium (15), and 1 (33) or 1.7-1.75 (37, 38) for the multicomponent system. 

In the case of zirconium and hafnium the lack of accessible dichlorides means that alkyl derivatives are generated via the corresponding homoleptic alkyl intermediates. With bulky 2,6-di-ferf-butylphenoxide the tris-benzyls [(ArO)ZrR3] can be isolated and studied. " The dialkyls [(ArO)2MR2] (M = Zr, Hf R = Me, benzyl) can also be isolated for bulky aryloxides. In the case of 2,6-diphenylphenols the monomethyl species [(ArO)3ZrMe] are readily formed by simple addition of parent phenol to the dimethyl compound. 

Scheme 15.32 Copper-catalysed azide-allg ne cycloaddition employing tris(benzyl-...

The synthesis of 2,3i5-tri-O-benzyl-yfl-D-ribofuranosyl fluoride and its oC-D-arabinofuranosyl analogue, has been accomplished by the reaction of the tri- -benzylated sugar with 2-fluoro-1-methylpyridin-ium tosylate - triethylamine. 

C-glycosides (32) and (33) using a Wittig reaction. The j8-glycoside (32) is formed initially, but it anomerizes to the a-glycoside (33) under the basic conditions of the reaction. Similar reactions were carried out with 2,3 5,6-di>0-iso-propylidene-D-manno- and -allo-furanose. Condensation of 2,3,5-tri-< -benzyl-D-ribofuranose with carbomethoxymethylenetriphenylphosphorane produced a... 

MCPc Tris(benzyl-mercapto)-mono(carboxy phenoxy)-phthalocyanine... 

Mugadza T, Nyokong T (2011) Synthesis and electrocatalytic behavior of cobalt(n)-tris (benzyl-mercapto)-monoaminophthalocyanine—single walled carbon nanotube nanorods. 

Unsaturated sugar derivatives continue to be used in glycoside syntheses. Scheme 9 illustrates an Interesting approach to the stereo-controlled synthesis of 2-deoxy-a-D-arabino-hexopyranosldes from 2,3,5-tri- -benzyl-D-arabinose by way of the Wittig-derived alkene (24). Alternatively, when the (Z)-alkene was treated with... 

---