2-Methyl-l-propen

Similarly alkylation (55) of l-N-pyrrolidino-2-methyl-l-propene (22) with propargyl bromide gave initial N alkylation to (23) with subsequent rearrangement to the allene (24). 

The addition of the anion of the racemic 2-methyl-2-propenyl sulfoxides, rac-2-methyl-3-(phenyl-sulfinylpl-propene and /w-3-(rerr-butylsulfinyl)-2-methyl-l-propene to 2-cyclopentenone gives mixtures of (E)- and (Z )-y-l, 4-addition products which are a mixture of diastereomers at sulfur2. The (T )-products usually predominate, with the relative proportions of the (Z)-product increasing as the reaction temperature is increased. No asymmetric induction originating from the stereocenter at sulfur was observed when the sulfoxide substituent was phenyl however, there was a marginal improvement in the case of the (Zi)-product when the sulfoxide substituent was ferf-butyl. 

Several review articles [37-40] have been written discussing the use of molecular sieves for the isomerization of light olefins, especially butene. The major driving force was the requirement in the 1990 amendments to the Clean Air Act in the United States that required the addition of oxygenates to gasoline in amounts up to 2.7wt% oxygen in the final gasoUne product [37]. The primary additive chosen to meet these requirements was MTBE, with lesser amounts of the ethyl ether (ETBE) or tert-amyl methyl ether (TAME) as supplements. One major possible route to meet these requirements was the isomerization of linear butenes (1-butene, cis-2-butene and trans-2-butene) into isobutene (2-methyl-l-propene). 

Synonyms y-Butylene CCRIS 2281 1,1-Dimethylethene u/35// -Dimethylethylene EINECS 204-066-3 Isobutene Isobutylene Methylpropene 2-Methyl-l-propene 2-Methylpropylene UN 1055. 

Methyl n-propan-2-ol, see ferf-Butyl alcohol Methyl propenate, see Methyl acrylate Methylpropene, see 2-Methylpropene 2-Methyl-l-propene, see 2-Methylpropene Methyl propenoate, see Methyl acrylate Methyl-2-propenoate, see Methyl acrylate 1 -Methylpropyl acetate, see sec-Butyl acetate 2-Methylpropyl acetate, see Isobutyl acetate 2-Methyl-1-propyl acetate, see Isobutyl acetate... 

An exceptionally interesting example of an intramolecular [3 + 2] cycloaddition, in which the diazo dipole and the olefinic C=C bond are separated by only one carbon atom, is outlined in Scheme 8.65. The thermal decomposition of the allenic tosylhydrazone sodium salt 267 produced 1,4-dihydropyridazine 269 (57). It is assumed that diazabicyclohexene 268 is a short lived reaction intermediate. This suggestion is supported by the observation that the generation of the diazocumulene l-diazo-2-methyl-l-propene in the presence of 3,3-dimethylcyclopropene also leads to 269. 

Scheme 21. The gas-phrase reactions of CoO+ with 2-methylpropane (iso-butane). Note that the compound labeled A is a 2-methyl-l-propene (iso-butylene) complex of Co , while the compound labeled B is a trimethylenemethane complex of Co. ...

The three compounds 2-methyl-l-propene(g), ds-2-butene(g), and trans-2-butene(g) are isomers of the formula C4H8 with standard free energies of formation of 58.07, 65.86, and 62.97 kJ-moD1, respectively. In the presence of a suitable metal catalyst, these three compounds can be interconverted to give an equilibrium mixture. What will be the percentage of each isomer present at 25°C once equilibrium is established ... 

It is interesting and of preparative value that although 1-bromo-2-methyl-l-propene and similar halides add to 1-hexene at both double-bond carbons, only one of the two 7r-allylic intermediates reacts with the amine. The result is that a mixture of six isomeric dienes is formed, but only one allylic amine is produced. Therefore the reaction is useful since the dienes and the amine are separated easily (2). 

Chloromethylphenyl acetate, (4-Acetoxyphenyl)methyl chloride, see 4-Acetoxybenzyl chloride, 3132b 2-Chloro-5-methylphenylhydroxylamine, 2792 Chloromethylphenylsilane, 2806 f 3-Chloro-2-methyl-l-propene, 1548 2-Chloromethylthiophene, 1836 A-Chloro-3-morpholinone, 1485 /V- C h I o ro -4 - n i t ro a n i I i n e, 2224 2-Chloro-5-nitrobenzaldehyde, 2645 2-Chloro-6-nitrobenzaldehyde, 2646... 

In several recent studies, nitro-substituted olefins have been shown to exhibit high electrophilic reactivities in superacid-promoted reactions.29 NMR studies have been used to identify some of the superelectrophilic intermediates in these reactions. For example, it was found that nitroethy-lene reacts with benzene in the presence of 10 equivalents of CF3SO3H to give deoxybenzoin oxime in 96% yield (eq 29). Since the reaction does not occur with only one equivalent of TfOH, it was proposed that the N,N-dihydroxy-iminium-methylium dication (51) is generated. In spectroscopic studies, l-nitro-2-methyl-l-propene (52) was dissolved in CF3SO3H, and at —5°C the stable dication (53) could be directly observed by and 13 C NMR spectroscopy (eq 30). 

The mild reaction conditions make the amination via organoboranes a suitable method for preparing functionally substituted amines. Thus, 3-(p-tolylthio)-2-methyl-l-propene is readily converted into the corresponding amine in a one-pot synthesis [9] (Scheme 7). 

Boran (l-Brom-2-methyl-l-propen-yloxy)-dimethyl- XIII/3a, 585... 

Dithiophosphonsaure 2-Methyl-l-propen- S-(2-diethylamino-ethylester)-0-ethylester XII/1, 590... 

This reaction of silyl ketene acetals with aldehydes, using 29 as a stoichiometric chiral reagent (Eq. 46), was reported by Reetz et al. [42]. The aldol addition of l-(trimethyl-siloxy)-l-methoxy-2-methyl-l-propene and 3-methylbutanal provides the aldol in only 57 % yield, but with 90 % ee. 

Elimination (El) usually occurs with loss of a proton, as in the formation of 2-methyl-l-propene from the /-butyl cation. 

C4H5F303S prop-2-enyl trifluoromethane sulfonate 41029-45-2 289.75 24.117 1.2 2818 C4H6CI2 1,1-dichloro-2-methyl-l-propene 6065-93-6 381.65 28.649 1,2... 

DICARBONYLCu -CYCLOPENTADIENYL) (2-methyl-i-propenyl-kC )iron and DICARBONYL(n -CYCLOPENTADIENYL)(ii. 2-METHYL. l-PROPENE)IRON(l+) TETRAFLUOROBORATE... 

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