DI-IERT-BUTYL

SCHEME 46. Oxidation of 2,6-di(iert-butyl)phenol with 02-Co(II) or Mn(II) complexes... 

Chloro-2,2-dimethyl-propanoyl-phosphanylidene)-l,2-di iert.-butyl- 3015... 

To a solution of the amine (1.4 g, 4.1 mmol) in THF (20 mL) at 0 °C was added Et3N (3.4 mL, 2.5 g, 24.6 mmol), followed by DMAP (about 0.01 g). To the reaction mixture was added di-iert-butyl dicarbonate (0.95 g, 4.92 mmol) and the solution was stirred at this temperature for 4 h. At this time the reaction mixture was quenched with ice and water (30 mL) and extracted with EtOAc (2 x 30 mL). The combined organic phases were washed with H20 (20 mL) and brine (20 mL), dried (Na2S04), and concentrated. Chromatography (5%-30% EtOAc/hexane) afforded the BOC-amine as a white solid (1.2 g, 90%). 

Low-pressure polymerizations were initiated by ultraviolet radiation in the presence of di-iert-butyl peroxide in bulk, dimethyl sulfoxide, or /ert-butanol solution at — 20°C to -I- 30°C. While the polymer precipitated out of solution at low conversion, in dimethyl sulfoxide, this precipitate was a gel which was partially transparent to light. At low conversions, the reaetion kinetics were treated as pseudohomogeneous processes [15]. 

Results of calculations confirm entropy change at a transformation of phenoles in phenoxyles radicals. The nature to sweep in this process is ambiguous. In a case alkyls substituents (Z = CH3, (CHj) 3) entropy change compounds A5 = + 3.4 +3.1 Entropy change 4-nitro-2,6-di-iert.butyl-... 

The widely used antioxidant and food preservative called BHA (butylated hydroxyanisole) is actually a mixture of 2-iert-butyl-4-methoxyphenol and 3-tert-butyl-4-methoxyphenol. BHA is synthesized from p-methoxyphenol and 2-methylpropene. (a) Suggest how this is done, (b) Another widely used antioxidant is BHT (butylated hydroxy-toluene). BHT is actually 2,6-di-iert-butyl-4-methylphenol, and the raw materials used in its production are p-cresol and 2-methylpropene. What reaction is used here ... 

Cross-coupling Reactions. Many cross-coupling reactions are critically influenced by the ligand used to form a reactive complex with the metal catalyst. Often, the use of di-iert-butyl(methyl)phosphine as a ligand leads to positive results. As an example, the Stille cross-coupling between a vinyl stannane and a primary alkyl bromide with -hydrogens, and therefore potentially subjected to undesired /3-hydride elimination, gives the best results with di-ferf-butyl(methyl)phosphine (eqs 1 and 2) ... 

Alternative names - 1,2-Bis(3,5-di-iert-butyl-4-hydtoxy-hydro-cimtamoyO-hydrazine... 

Although 2,3-di-iert-butyl-l,3-butadiene has four adjacentp orbitals, the bulky tert-butyl groups prevent the diene from adopting the s -cis conformation needed for the Diels-Alder reaction. Thus, this diene does not undergo a characteristic reaction of conjugated dienes. 

SItBu l,3-di(iert-butyl) TIMEN" " tris[2-(3-arylimidazol-... 

Dibutyl acetal see IJ-Dibutoxytrimethylamine, D-00221 Di-iert-butyl acetal see IJ-Di-iQri-butoxytrimethylamine, D-00222... 

---