2,6-Di-t-butyl-4-methylpyridine

The fluorodestannylation with XeF2 takes place rapidly at room temperature in the presence of 2,6-di-t-butyl-4-methylpyridine, fast enough for introducing the short-lived 1SF isotope, and is thought to involve the initial formation of triflic hypofluoride, F3CSO3F, and then its adduct with the vinyltin compound (Equations (74)-(76)).228... 

Chiral Yb catalyst = Yb(OTf)3 + (fl)-BINOL + DBU.DTBP 2,6-Di-t-butyl-4-methylpyridine. DPP 2,6-Dimethylpyridine. DTBMP 2,6-Di-f-butyl-4-methylpyridine. 

Other bases such as pyridine, lutidine, Et3N, polymer-bound 2,6-di-t-butyl-4-methylpyridine, and 2,4,6-trialkyl-substituted pyrimidines were also used. The commercially available IV,iV-diisobutyl-2,4-dimethyl-3-pentylamine is a very convenient base to prepare the vinyl triflates. In the case of nonfunc-tionaUzed ketones, anhydrous Na2C03 has been proved to be very successful. ... 

The danger of formation of sugar pyridinium salts when using tri-fluoroacetic anhydride in pyridine may be avoided by using 2,6-di-t-butyl-4-methylpyridine. Reaction of carbohydrate triflates with cyanide ion allows inversion at the hydroxy carrying centre either sodium cyanide or tetra-n-butylammonium cyanide were used in a one-... 

Two papers by the same authors have appeared on the alkylation of monosub-stituted benzene derivatives with vinyl triflates (e.g. R2C=CPh03SCF3, where R = Ph, Me, and 1-cyclohexenyl to cyclo-octenyl triflates). The reactions are carried out in the presence of 2,6-di-t-butyl-4-methylpyridine (a non-nucleo-philic base, to neutralise the triflic acid formed during reaction) and a large excess of the aromatic substrate. The mechanism is thought to involve a vinyl cation intermediate. 

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