Sodium t-butoxide

Under an atmosphere of nitrogen a flask was charged with the step 2 product (18.70 mmol), aniline (39.27 mmol), palladium dibenzanthracene (0.37 mmol), t-butylphosphine (0.75 mmol), and 100 ml toluene. The reaction mixture stirred for 10 minutes and was then treated with sodium t-butoxide (38.33 mmol) and continued stirring for 24 hours. The mixture was diluted with 3 liters of toluene and filtered through a plug of silica and celite, concentrated, and a dark brown oil obtained. The residue was purified by flash column chromatography on silica gel using a mixture of ethyl acetate/hexanes, 1 10, respectively, and 6.8 g product isolated as a pale yellow powder. 

A mixture consisting of phenoxazine (54 mmol), sodium t-butoxide (77 mmol), tris(dibenzylidene acetone)dipalladium(0) (1.1 mmol), and tri(/-butyl)-phosphine (1.1 mmol) were dissolved in 250 ml of xylene and then heated to 80°C for 12 hours. Thereafter, the reaction mixture was cooled to ambient temperature, quenched with 200 ml of distilled water, and extracted with xylene/water, 1 1. 

N-Bis(trimethylsilyl)acetamide, 34 Butyllithium, 56, 150, 157, 193, 322 sec-Butyllithium, 188 Butyllithium-Potassium t-butoxide, 56 Butyllithium-Sodium t-butoxide, 59 Butyllithium-Tetramethylethylene-diamine, 56, 57 t-Butylmagnesium bromide, 59 Butylpotassium-Tetramethylethylene-diamine, 59 Butylsodium, 59... 

Under continuous nitrogen flow, a reaction flask was dried with a propane torch flame and then cooled to ambient temperature. The flask was charged with 180 ml of toluene, palladium acetate (0.5 mmol), and tri-t-butylphosphine (2.0 mmol) and stirred at ambient temperature until a thick light yellow suspension was obtained. This mixture was then treated with 4-n-butylaniline (10 mmol), the Step 1 product (10 mmol), and sodium t-butoxide (22 mmol) and heated overnight at 80°C. The reaction mixture was poured into 1000 ml of methanol where a brownish precipitation slowly appeared, which was isolated by filtration. The brown solid was dissolved in 50 ml of CCI3H and re-precipitated in 500 ml of methanol, and the product was isolated in 45.0% yield as a brown powder having a M of 7728 daltons with a PDI of 2.12. 

French chemists2 report that treatment of trans-1,2-dibromocyclohexane (1) with the complex base sodium amide-sodium t-butoxide produces cyclohexene (2, 36% yield) and 1-bromocyclohexene (3, 60% yield). Use of either base (separately) leads... 

An additional example (Figure 4) of stereochemical control was observed by workers at BMC in cyclization of ester enolates (6). Cyclization of the ethyl ester initiated by sodium t-butoxide in hexane produced a 12 88 ratio of cis traps cyclopropanes. 

On treatment with potassium t-butoxide instead of sodium t-butoxide in THF, dioxetane 2 decomposed more rapidly (kCTICL - 0.11 s 1) to emit a flash of light with AmaxCTICL = 539 nm. The chemiluminescence spectrum is illustrated in Fig. 3 together with chemiluminescence spectra for TBAF system and for the other alkaline metal t-butoxide (vide infra). 0 decreased to 4.5 x 10 though it was yet effective 10 times more than that in the TBAF system. Finally, we carried out the decomposition of 2 with lithium t-butoxide in THF. Lithium ion in general coordinates strongly to oxidoaryl anion in an organic solvent because of the smallest ion radius, thus, we did... 

N-Arylatwn. Secondary amines are arylated by ArCl under the following conditions heating with Ni(acac)2, 3,5,6,8-tetrabromo-l,10-phenanthroline, sodium t-butoxide, and PMHS in toluene at 130°. ... 

Benzofurans. - Treatment of a mixture of o-dichlorobenzene and cyclohexanone with sodamide and sodium t-butoxide yields tetrahydrobenzof uran by the aryne mechanism outlined in Scheme 1. The formation of the... 

Sodium t-butoxide (CHa)aC-ONa could be reacted with methyl bromide. This reaction gives the desired product methyl tert-butyl ether (CHa) 3C-0 -CH3. 

Alkoxides are useful reagents they are used as powerful bases (stronger than hydroxide). Sodium t-butoxide and ethyl bromide (CH3CH2Br) are mixed together to give CeHi O. This reaction illustrates nucleophilic substitution. Ethyl bromide is an alkyl halide, and nucleophilic substitution is typical of such organic compounds. Nucleophilic substitution may be generalized as... 

Due to the fact that the only organic compound present after tert-butyl bromide is added to sodium ethoxide is ethanol, this reaction cannot be the same as the one discussed above (when ethanol was added to sodium t-butoxide). In fact, this reaction is one of elimination. Recall that in the dehydrohalogenation to produce alkenes, the base (OE0) pulled a hydrogen ion away from carbon, and simultaneously a halide ion separated. This is exactly what happens when sodium ethoxide and t-butyl bromide are mixed together, except that in this case the sodium ethoxide replaces 0H as the base. The reaction may be written as ... 

In some, apparently straightforward, displacements, more detailed mechanistic study reveals the operation of alternative mechanisms. For example the reaction of either 3- or 4-bromopyridine with secondary amines in the presence of sodamide/ sodium t-butoxide, produces the same mixture of 3- and 4-dialkylaminopyridines this proceeds via an elimination process (Sn(EA) - Substitution Nucleophilic Elimination Addition) and the intermediacy of 3,4-didehydropyridine (3,4-pyr-idyne)." That no 2-aminated pyridine is produced shows a greater difficulty in generating 2,3-pyridyne, it can however be formed by reaction of 3-bromo-2-chloropyridines with butyllithium" or via the reaction of 3-trimethylsilyl-2-trifluoromethanesulfonyloxypyridine with fluoride." ... 

Treatment of dithiol (135), prepared by the reaction of p-methylacetophenone with carbon disulfide in the presence of sodium t-butoxide, with piperidine, piperazine or morpholine and excess formaldehyde in the presence of a catalytic amount of hydrochloric acid resulted in a Mannich-type reaction to give the 1,3,5-dithiazepines (136) in high yields (Equation (6)) <88Mi 916-01 >. 

Both sodium t-butoxide and potassium hexamethyldisilazide were used in palladium-catalyzed ketone arylations. While reactions involving electron-neutral or electron-rich aryl halides were more selective for monoarylation when JCHMDS was used, sodium f-butoxide gave good selectivity with electron-poor aryl halides, without direct decomposition of the aryl halide. Bis(diph-enylphosphino)ferrocene-ligated palladium complexes were... 

Sodium t-butoxide is usually used in palladium-catalyzed ketone arylations. However, this base was incompatible with aryl halides substituted with an electron-withdrawing group. Replacement by NaHMDS led to a-aryl ketones in good yields (eq 14). ... 

Alkylation and acylation of dithiane oxides are highly stereoselective processes. In such transformations, it is noticed that the anti substrate leads to the syn acyldithiane oxide (Scheme 4.55), with the choice of base being pivotal in the process. The use of butyllithium for acylation and sodium t-butoxide/butyllithium mixtures for alkylation with aldehydes tends to give the cleanest and most efficient reactions. Of late, simple 2-substituted dithiane oxides have been prepared with very high enantioselectivity, and such compounds have become the preferred starting materials for the various systems under scrutiny. 

The Hakomori method has also been used extensively in the methylation of carbohydrates however, yields were typically low and non-sugar products were observed. Subsequent studies by Ciucanu and Kerek [40] led to the conclusion that OH and H were more effective bases than the methylsulfinyl carbanion. These authors developed a new method for the permethylation of carbohydrates using CH3I and solid NaOH in DMSO. This reaction is relatively clean, proceeds to completion in about 6-7 min, and gives very high yields ( 98%). The derivatization may also be performed with KOH, NaH (excess) and sodium t-butoxide. Ciucanu and Kerek have extensively reviewed the experimental parameters and have published a table of procedures, reagents, reaction times and yeilds for various other versions of Ihe permethylation reaction [40]. 

In a 250-mL Schlenk flask were added copperfi) chloride (1.0 g, 10.10 mmol), l,3-Z>w(2,6-diisopropylphenyl)-imidazolium chloride (4.29 g, 10.10 mmol), and sodium t-butoxide (0.97 g, 10.10 mmol). To this flask was added dry THF (100 mL) under Ar, and the mixture was magnetically stirred for 20 h at RT. The mixture was then filtered through a plug of Celite and the solvent evaporated in vacuo to give a white solid (4.59 g, 9.40 mmol, 93%). ... 

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