Tert-BuCl

This impressive cascade reaction begins with the formation of a small amount of the fert-butyl cation by reaction of A1C13 with tert-BuCl. The fert-butyl cation abstracts a hydride ion... 

AlMe3—tert-BuCl in MeCl. To 15 ml. isobutylene in 60 ml. methyl chloride stirred at —35°C., 8.3 X 10"5 mole AlMe3 (0.2 ml. of 4 vol. % AlMe3 in MeCl solution) was added no reaction occurred. Subsequently, a total of —5.5 X 10 6 mole of terf-butyl chloride was added dropwise (a 1% tert-butyl chloride solution was used) immediate polymerization occurred the yield was 1.469 grams or 14% the viscosity average molecular weight was 240,300. 

Most group 1 phospholides have been prepared through alkali metal cleavage of a phosphole P-Ph bond and, after destruction of phenyl-derived byproducts (with tert-BuCl AlCl3, etc.), used in situ [3]. However, this convenient method is poorly adapted to sensitive chemistry and effort has been devoted to isolating pure alkali metal phospholides. When not substituted by chromophores, these are colorless, and sometimes pyrophoric materials. 

Kennedy and Castner [324] have studied the reaction of tert.-BuCl with McjCpAl (cp = cyclopentadiene). They assumed the formation of the ion pair tert.-Bu "Me2cpAlCl , yielding either neopentane or /er/.-Bu-cyclopenta-... 

Lately Brown investigated the exo endo solvolysis rate ratio of 2-norbomyl chlorides in aqueous acetone with widely varied water content This work included linear correlations of log k, on log k , as well as those of log k, and log k, , on log k (tert-BuCl) the latter is a model k process. The data obtained agree with the assumptions that the solvolysis of exo and endo epimers are either k and k processes, respectively, or they are both processes of type k the results were found to be independent of the leaving group and hence of F-strain (cf. According to Brown introducing the a-CHj group to epimeric 2-norbomyl chlorides results in about the same kinetic effect the solvolysis of exo- and endo-norbornyl derivatives, both secondary and tertiary, proceeds by route k. ... 

The advantage of the wave function (2.2) over e.g. the choice of a more familiar Hartree-Fock (HF) wave function is its ease of interpretability, as we now illustrate for the tert-butylchloridc (BuCl) 5.yl reaction system [10],... 

This reaction looks very similar to the reaction of hydroxide ion with methyl chloride presented earlier, but with the negative oxygen of the acetate anion acting as the nucleophile. (The CH3C02H shown over the arrow is the solvent for the reaction.) However, investigation of this reaction in the laboratory has shown that the reaction rate depends only on the concentration of tert-butyl chloride (r-BuCl). It is totally independent of the concentration of acetate anion. The reaction follows the first-order rate law ... 

AlMe3-ferf-BuCl in a-Pentane. To a charge of 15 ml. isobutylene in 60 ml. n-pentane stirred at —35°C., 1.05 X 10 3 mole of an AlMe3 (2 ml. of 8 vol. % AlMe3) was added in n-pentane solution no reaction occurred. Subsequently, a tert-butyl chloride in n-pentane solution was added drop-wise until a total of 1.66 X 10 4 mole of tert-butyl chloride was introduced (0.9 ml. of a 2% tert-butyl chloride in n-pentane solution) however, no polymerization occurred, and no methanol-insoluble polymer was formed. 

We first applied the solvatochromic equation (SCE) to solvolysis of tert-butyl chloride (t-BuCl) to determine if the method could give a reasonable result for this much-studied reaction (7). Abraham et al. (11) had previously attempted correlation of these rates with the SCE without the cavity term, but as Bentley and Carter (12) have noted, an unsatisfactory result was achieved (7). First, TFE and hexafluoroisopropyl alcohol (HFIP) did not fit the correlation. Second, no rate dependence on solvent nucleophilicity 0 was found, despite other works indicating a weak dependence on this parameter (12, 13). Also, different correlations were observed for hydroxylic and nonhydroxylic solvents Bentley considered this finding to indicate that the dehydrohalogenation transition state (in nonhydroxylic solvents) and the solvolysis transition state (in hydroxylic solvents) were significantly different and thus concluded that the two types of reactions should not be included in the same correlation. 

We have applied DPA to tert-butyl and iec-butyl chlorides. As discussed in other sections, the difference in stabilities we obtained was in excellent agreement with that provided by other methods. The most important point, however, is that the DPA onset for iec-BuCl could be clearly determined, in spite of the fact that iec-Bu readily rearranges to tert-Bu. This is explained by the fact that the DPA are entropy-driven, endoergic reactions. This makes DPA extremely valuable for the study of relatively unstable species. Examples of such processes are known. They are currently under study in our laboratories. 

So far only one example of furan alkylation assisted by arene complexes has been reported. D.J. Milner has shown that furan reacts with tert-hutyl chloride in the presence of (TX -mesitylene)Mo(CO)3 to afford a mixture of 2-fert-butyl-furan and 2,5-di-tert-butylfuran in 65-80% yields [20]. Both mono- and disub-stituted furans can be prepared as the major product by changing the furan/t-BuCl ratio. Although there is only one report of this reaction, the ability to synthesize mono- and disubstituted furans in a simple manner reflects the potential of this methodology which can be used for preparing substituted furans, that are valuable synthetic materials. 

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