Tert-alkyl chloride

The addition of these reagents at the end of the polymerization reaction resulted in the consumption of the catalyst and the formation of tert-alkyl chloride chain ends on the PIB rather than the desired nucleophilic substitution (5). 

SE-Substitution has been found when a-bromoallylsilane 7 is treated with tert-alkyl chloride in the presence of TiCLt at —78°C to give 9440. The reaction with a-bromoethylbenzene under the same conditions yields the corresponding indane 96. Apparently, the intermediate 95 may further undergo an intramolecular Friedel-Crafts reaction under these conditions (equation 74)... 

The chemical reactivities of such titanium homoenolates are similar to those of ordinary titanium alkyls (Scheme 2). Oxidation of the metal-carbon bond with bromine or oxygen occurs readily. Transmetalations with other metal halides such as SnCl4, SbClj, TeCl, and NbCl, proceed cleanly. Reaction with benzaldehyde gives a 4-chloroester as the result of carbon-carbon bond formation followed by chlorination [9]. Acetone forms an addition complex. No reaction takes place with acid chloride and tert-alkyl chlorides. 

All examples discussed in Sections 3-1 and 3 2 follow the simple Scheme outlined on the bottom of Figure 2, and the results can be explained by considering the competition of RX/R and PX/P" for the tt nucleophile. This analysis may fail, however, if the addition reaction is part of a more complex reaction sequence. A well-known example is the tert. alkylation of siloxyalkenes with tert.alkyl chloride/Lewis acid mixtures. The rapid desilylation of the initially generated siloxycarbenium ion prevents this ion to act as an electrophile towards other ir systems. 

SE-Substitution has been found when a-bromoallylsilane 7 is treated with tert-alkyl chloride in the presence of TiCU at —78°C to give The reaction with... 

A direct procedure for tert-alkyl-alkynyl coupling using tert-alkyl chloride or bromide was reported by Negishi and Baba. The reaction provides successive geminal alkyl-alkynylation of ketones (Scheme 6.6) [6]. 

Crich, D. and Fortt, S. M., A new method for the synthesis of tert-alkyl chlorides from tert-alcohols. 

Titanium(IV) is a powerful but selective Lewis acid which can promote the coupling of allylsilanes with carbonyl compounds and derivatives In the presence of titanium tetrachlonde, benzalacetone reacts with allyltnmethylsilane by 1,4-addition to give 4-PHENYL-6-HEPTEN-2-ONE. Similarly, the enol silyl ether of cyclopentanone is coupled with f-pentyl chloride using titanium tetrachlonde to give 2-(tert-PENTYL)CYCLOPENTANONE, an example of a-tert-alkylation of ketones. 

The carbocation electrophile in a Friedel-Crafts reaction can be generated in ways other than by reaction of an alkyl chloride with AICI3. For example, reaction of benzene with 2-methylpropene in the presence of H3PO4 yields tert-butylbenzene. Propose a mechanism for this reaction. 

The reaction of tert-alkyl Grignard reagents with carboxylic acid chlorides in the presence of a copper catalyst provides ieri-alkyl ketones in substantially lower yields than those reported here.4,14 The simplicity and mildness of experimental conditions and isolation procedure, the diversity of substrate structural type, and the functional group selectivity of these mixed organocuprate reagents render them very useful for conversion of carboxylic acid chlorides to the corresponding secondary and tertiary alkyl ketones.15... 

There is direct evidence, from IR and NMR spectra, that the re/T-butyl cation is quantitatively formed when tert-butyl chloride reacts with AICI3 in anhydrous liquid HCl. In the case of alkenes, Markovnikov s rule (p. 984) is followed. Carbocation formation is particularly easy from some reagents, because of the stability of the cations. Triphenyhnethyl chloride and 1-chloroadamantane alkylate activated... 

Schrauzer and co-workers have studied the kinetics of alkylation of Co(I) complexes by organic halides (RX) and have examined the effect of changing R, X, the equatorial, and axial ligands 148, 147). Some of their rate constants are given in Table II. They show that the rates vary with X in the order Cl < Br < I and with R in the order methyl > other primary alkyls > secondary alkyls. Moreover, the rate can be enhanced by substituents such as Ph, CN, and OMe. tert-Butyl chloride will also react slowly with [Co (DMG)2py] to give isobutylene and the Co(II) complex, presumably via the intermediate formation of the unstable (ert-butyl complex. In the case of Co(I) cobalamin, the Co(II) complex is formed in the reaction with isopropyl iodide as well as tert-butyl chloride. Solvent has only a slight effect on the rate, e.g., the rate of reaction of Co(I) cobalamin... 

Tin-based reagents are not always snitable owing to the toxicity of organotin derivatives and the difficulties often encountered in removing tin residues from the final product. Therefore, the same authors have carried out additional experiments with 17d and several different alkyl halides under tin-free conditions. The treatment of 16d with tert-butyldiphenylsilyl chloride (TBDPSCl) and triethylamine in the presence of silver triflate in CH2CI2 affords the bis(silyloxy)enamine 17d in 92% yield (Scheme 17). When the radical reaction was carried out with ethyl iodoacetate in the presence of 2,2 -azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70) as the initiator in CH2CI2, the oxime ether 19 was obtained in 83% yield (Scheme 17). 

More recent patents describe the following preparation from a-methylcinnam-aldehyde. a-Methylcinnamaldehyde (from benzaldehyde and propionaldehyde) is hydrogenated to a-methyldihydrocinnamic alcohol. The alcohol is alkylated with tert-butyl chloride or isobutene to 4-tert-butyl-o -methyldihydrocinnamic alcohol, which is subsequently dehydrogenated to the desired aldehyde [152, 153]. 

Clayden and Julia reported the 1,3-C,H insertion reaction of lithium carbenoid (69) derived from a primary alkyl chloride (68) by H-Li exchange reaction (eqnation 19). Treatment of 68 with a mixture of n-BuLi and tert-BnOK gave three prodncts. These... 

Preparative use could be made also from the perturbed redox catalysis (Eqs. (84)—(86), (93)-(95). For example, alkylated aromatic hydrocarbons that are difficult to obtain by Friedel-Crafts alkylation could be synthesized in this way. The most suitable alkylating agent is tert-butyl chloride or bromide -ass) alkyla-... 

Miscellaneous a-Substituted Peroxides. 3-Aryl-3-(tert-alkylperoxy)-phthalides (8) are prepared from the corresponding 3-chlorophthalides and iert-alkyl hydroperoxide. 2-Methyl-2-((erl-alkylperoxy)-l,3-benzodioxan-4-ones (9) are obtained from o-acetylsalicyloyl chloride and tert-alkyl hydroperoxides. Trisubstituted 2-(ferr-alkylperoxy)-l,3-dioxolan-4-ones (10) are synthesized from sterically favored cr-acyloxy acid chlorides and tert-alkyl hydroperoxides. 

Exercise 17-27 If methyl iodide gives mainly C-alkylation with the enolate anion of 2-propanone, which of the following halides would you expect to be candidates to give O-alkylation tert-butyi chloride, phenylmethyl chloride, 3-chloropropene, neo-pentyl chloride ... 

The radical anion initially formed on reduction of 65 could be trapped with tert-butyl chloride in DMF solvent.101 The yields of alkylated amide were low, and the problem was traced to the rate of competitive dimerization. 

The catalyst for the reaction between PVC and the high cis-1,4-polybutadiene was a dialkylaluminum halide—e.g., Et2AlCl—or sesquihalide. The catalyst could be added from an external source or could be generated in situ—e.g., by the reaction of an aluminum alkyl with either titanium tetrachloride or a reactive organic halide such as benzyl chloride or tert-butyl chloride. The concentration of Et2AlCl was varied from 0.2-5% by weight based on PVC, although the preferred concentration was between 0.5 and 1.5 wt %. 

Compound A is therefore 2-methylpropane, the two alkyl chlorides are tert-butyl chloride and isobutyl chloride, and alkene B is 2-methylpropene. 

Friedel-Crafts alkylation occurs when biphenyl is treated with tert-butyl chloride and iron (III) chloride (a Lewis acid catalyst) the product of monosubstitution is p-ferf-butylbiphenyl. All the positions of the ring that bears the tert-butyl group are sterically hindered, so the second alkylation step introduces a tert-butyl group at the para position of the second ring. 

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