2.6- tert-butyl-4-methylpyridine

A similar Schiff base-titanium complex has been applied to the aldol reaction with 2-methoxypropene as nucleophile using 2,6-tert-butyl-4-methylpyridine as an additive [117]. Although the reaction conducted in toluene or ether solution failed to provide the desired addition product, excellent chemical yields and enantioselectivities were attained by using 2-methoxypropene as the solvent (Scheme 14.40). 

Addition of a bulky pyridine base Some workers have added an equivalent of 2,6-di-tert-butylpyridine or 2,6-di-tert-butyl-4-methylpyridine to the glycosylation mixture. While the reasons for this addition have not been discussed, one can note that according to a speculative equation for the glycosylation reaction ... 

C-Alkylation of weakly activated methylpyridines to yield the isopropyl and tert-butyl derivatives (35-40%), which normally requires the use of strong bases, such alkyl lithiums, is earned out effectively using a phase-transfer catalyst and aqueous sodium hydroxide on the /V-methylpyridinium salts. The pyridines are regenerated by reaction with sodium acetate or sodium 4-toluenethiolate [134]. 3-Methylpyridine fails to react under these conditions and the synthesis of 2-ethylpyridines by this procedure is also unsuccessful. 

A commercial sample of 2,6-di-tert-butyl-4-methylpyridine from Fluka AG was purified through a short column of silica gel by eluting with hexane. Alternatively it may be prepared according to the procedure reported in Organic Syntheses. ... 

Di-tert-butyl-4-methylpyridine Pyridine, 2,5-bis(l,1-dimethylethyl)-4-methyl- (9) (38222-83-2)... 

OTIPS (BrCl2C)2, PPI13, MeCN, 2,6-di-tert-butyl-4-methylpyridine... 

Mitsunobu Reaction for Exocyclic N2-Alkylation on a Purine Scaffold (Fig. 16).47 2,6-Di-tert-butyl-4-methylpyridine (1.54 g, 7.5 mmol, 0.3 M) is added to freshly distilled CH2C12 (25 ml) at 0° under N2. To this solution is added trifluoroacetic anhydride (706 pi, 5.0 mmol, 0.2 M) and the mixture is stirred for 5-10 min. The solution is then transferred to the resin 83 and the flask is vortexed and vented several times to relieve pressure. The flask is shaken for 6-12 h after which the solvent is removed and the resin washed with dry CH2C12 (5 x 25 ml) with vortexing between each rinse. The resulting resin 84 is dried. 

Heating the trifluoromethanesulfonate 89 in the presence of 2,6-di-tert-butyl-4-methylpyridine gave methyl 3,5-anhydro-2,6-dideoxy-/J-D-xylo-hexofuranoside 91. This rearrangement involves oxane-ring contraction 90 followed by internal sulfonate displacement.353... 

Both AgOTf and AgSbF6 (10mol%) were the best catalysts for this transformation, and the reaction was conducted in the presence of an hindered base, 2,6-di-tert-butyl-4-methylpyridine (DTBMP). The azomethine ylide CC intermediate has been identified in a test reaction in the absence of DMAD, via mass spectrometry. The scope and limitations have been thoroughly studied for reaching pyrroloisoquinoline scaffold, which is a substructure of the lamellarin alkaloid family. 

B. 2,6-Di-tert-butyl-4-methylpyridine (2). To 119-128 g (0.33-0.36 mol) of crude pyrylium salt in a 5-L, three-necked, round-bottomed flask equipped with a mechanical stirrer is added 2 L of 95% ethanol. The mixture is cooled to -60°C with an isopropyl alcohol-dry ice bath and to the fine slurry is added, with stirring, in one portion 1 L of concentrated (d 0.90) ammonium hydroxide also cooled to -60°C. The yellow reaction mixture is held at -60°C for 30 min, then allowed to warm to -40°C and maintained at that temperature for 2 hr, during which time the slurry dissolves. The mixture is then allowed to spontaneously warm to room temperature (Note 6). The reaction mixture is divided into two portions. Each portion is poured into a 4-L separatory funnel, 1 L of aqueous 10% sodium hydroxide is added, and the mixture is extracted with four 250-mL portions of pentane (Note 7). The extracts from both portions are combined and... 

C14H1806 (+)-(4,6-0-benzylidene)methyl-a-D-glucopyran 3162-96-7 25.00 1.2022 2 27723 C14H23N 2,6-di-tert-butyl-4-methylpyridine 38222-83-2 23.00 0.8979 2... 

C7H17N methylethyl-tert-butyl amine 52841-28-8 190.00 16.907 2 14098 C8H11N 2-ethyl-6-methylpyridine 1122-69-6 216.18 9.006 2... 

Abbreviations Ac acetyl Bn benzyl BSP 1-benzenesulfinyl piperidine BTIB bis(trifluoroacetoxy)iodobenzene DAST (diethylamino)sulfur trifluoride DDQ 2,3-dichloro-5,6-dicyano-/)-benzoquinone DMDO dimethyldioxirane DMTSF dimethyl(methylthio)sulfonium tetrafluoroborate DMTST dimethyl(methylthio)sulfonium triflate DTBMP 2,6-Ai-tert-butyl-4-methylpyridine DTBP 2,6-di-tert-butylpyridine DTBPl 2,6-di-tert-butylpyridinium iodide FDCPT l-fluoro-2,6-dichloropyridinium triflate FTMPT l-fluoro-2,4,6-trimethylpyridinium triflate IDCP iodonium dicollidine perchlorate IDCT idonium dicollidine triflate LPTS 2,6-lutidinium p-toluenesulfonate LTMP lithium tetramethylpiperidide Me methyl MPBT S-(4-methoxyphenyl) benzenethiosulflnate NBS A-bromosuccinimide NIS A-iodosuccinimide NlSac A-iodosaccharin PPTS pyridinium p-toluenesulfonate TBPA tris(4-bromophenyl)ammoniumyl hexachloroantimonate Tf trifluoromethanesulfonyl TMTSB methyl-bis(methylthio)sulfonium hexachloroantimonate TMU tetramethylurea Tr trityl TTBP 2,4,6-tri-tert-butylpyrimidine. 

Pyridine is added to neutralize small amounts of hydrogen iodide, which is often present in iodotrimethylsilane as a result of hydrolysis by contact with moisture. The amount of by-products, including cyclohexyl iodide, is reduced by the presence of pyridine. Hindered pyridine bases such as 2,6-di-tert-butyl-4-methylpyridine" have also been used for this purpose by the submitters. The pyridine bases do not appear to react with iodotrimethylsilane. 

BCI3, toluene, 2,6-di-tert-butyl-4-methylpyridine, —78"C, 87% yield. In the synthesis of ditriptophenaline, an FMOC group did not survive the basic TBAF or BF3-Et20. ... 

Proton Traps. 2,6-Di-tert-butyl-4-methylpyridine (DBMP) and 2,6-di-tert-butyIpyridine (DtBP) are hindered bases incapable of reacting with electrophiles other than protonic acids. Consequently, they can be successfully used for the trapping of protons during their transfer to monomer (174. 175). At the same time they can disseminate between the two major initiation mechanisms encountered in cationic polymerization, that is, protonic initiation or carbenium initiation (176). 

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