Terf-Alkyl

Primary and secondary alkyl halides react with the reagents R3S11M largely by substitution, but terf-alkyl halides, if they can, undergo... 

The activation energy for rotation about the terf-alkyl-to-triptycyl bond was 36.6 kcal/mol for 101, and the frequency factor was 10 7 sec 1. It should be noted that the barrier to rotation is raised by ca. 4 kcal/mol by going from a bis(methoxycarbonyl)etheno bridge to a benzeno bridge. The equilibrium constant ( sc/ap) was 2.0, as expected on statistical grounds. 

At 30°C. both ki and k2 increase with increasing size of the terf-alkyl and f erf-aralkyl groups. Apparently, the elimination of oxygen from the presumed tetroxide intermediate is accelerated by an increase in the size... 

Activation of two Si—Si bonds in bis(disilanyl)alkanes with palladium(O) bis(tert-alkyl isocyanide) induced the formation of the cyclic bis(silyl)palladium(II) bis(terf-alkyl isocyanide) complexes (100) and disilanes described schematically in Scheme 42. These complexes were found to react with phenylacetylene, affording different amounts of five-membered cyclic products and acyclic products which are derived from the insertion of the alkyne into the general intermediate complex 101 (Scheme 42, equation 54). The bis(silanyl)dithiane palladium complex (102) was isolated and characterized in the solid state the two silicon atoms, the two isocyano carbons and the palladium atom are nearly in a plane with a short cross-ring Si—Si distance of 2.613(2) A, suggesting the possibility of covalently bonded two Si—Si atoms in the four-membered ring. Similar reaction with cyclic disilanes afforded oligomers, and cyclic 20-membered compounds have been prepared in the presence of nitriles248,249. 

This and the 4-nitrobenzoates of homologous terf-alkyl hydroperoxides explode in contact with flame. 

The reaction described here is probably responsible for the slow decomposition of many oxaziranes at room temperature. 2-terf-Alkyl-oxaziranes are stable at room temperature for unlimited periods radical attack on the a-C-atom of the IV-alkyl group is not possible. By contrast, oxaziranes containing a C—H group which is alpha to the N-atom are unstable at room temperature on keeping they are largely decomposed within a few weeks. 

Di-terf-alkyl oxalates decompose to olefins (80-100% yield) at 140-1600.34... 

It should be noted that tBA is currently the only acrylate monomer that undergoes living anionic polymerization to afford polymers with up to a few 10 gmor or higher values rmder suitable conditions. This means that it is necessary to synthesize functional terf-alkyl esters of acrylic acid, as shown in Figure 31, in order to achieve the living anionic polymerization of protected acrylate... 

---