L-methyl-2- -pyrrolidine

The synthesis of 5-aminothiazoles via the reaction of isocyanate derivatives with aminomalononitrile p-toluenesulfonate (AMNT) has been investigated. It was found that AMNT 12 reacted with alkyl and aryl isothiocyanates in l-methyl-2-pyrrolidine (NMP) to furnish 5-amino-2-(alkylamino)-4-cyanothiazoles (13a) and 5-amino-2-(arylamino)-4-cyanothiazoles (13b-c) in 44-81 % yields. " ... 

Addition of DMAD to l-methyl-2-pyrrolidine dimethylacetal (69) in dioxane108 gave no 70, but the indoline 75, the isomeric pyrrolidones 71 and 72, and the pyrroline 76 were obtained using benzene as solvent the 1 1 adduct (73) was the major product. With DMAD, compound 73 gave 75, presumably via 74. 

Nicotine or (S)-3-(l-methyl-2-pyrrolidin-2-yl) pyridine Biopesticide Predominantly respiratory action Tobacco extracts against sucking insects 11-15... 

Methyl isobutyl ketone, methyl ethyl ketone, acetone, dimethylformamide, tetrahydrofuran, l-methyl-2-pyrrolidine, acetonitrile and related polar solvents Freon and freon ether type solvents are best for the more heavily (8) fluorinated polymers... 

The inorganic tin-containing products are insoluble in all tested liquids consistent with the behavior of other tin-containing cross-linked ionomers. Liquids tested include DMF, DMA, HMPA, DMSO, l-methyl-2-pyrrolidine, acetonitrile and acetone. 

In another example, the aiylation of ketone enolates was achieved indirectly via an intermolecular Heck reaction. In this case, the diastereoselectivity is induced by chelation of a metal-coordinating auxiliary. The inexpensive and commercially available amino alcohol (6()-l-methyl-2-pyrrolidine-methanol was selected as a suitable chiral auxiliary (Scheme 13.47). The prolinol vinyl ether 182 was... 

The addition of ethyl acrylate to 1,2-dimethyl- -piperideine 163), l-methyl-2-ethyl-zJ -piperideine 164), and 1,2-dimethyl- -pyrrolidine 216,217) occurs, yielding both possible enamine structures (138 and 139, n=I,2). 

Reduction of l-methyl-2-alkyl-.d -pyrroline and l-methyl-2-alkyl-.d -piperideine perchlorates with complex hydrides prepared in situ by partial decomposition of lithium aluminum hydride with the optically active alcohols (—)-menthol and (—)-borneol affords partially optically active l-methyl-2-alkyl pyrrolidines (153, n = 1) and 1-methy 1-2-alkyl piperideines (153, n = 2), respectively (241,242). 

One of the most intensively studied protic chiral ligands, which moreover allows enantioselectivities of up to 95% ee, is the proline-derived (25 )-l- [(25,)-l-methyl-2-pyrrolidinyl]methyl -2-pyrrolidine methanol (6)19-21. 

Cyclische a-Amino-ketone erleiden bei der Elektroreduktion eine Strukturverande-rung l-Methyl-2-athyl-3-oxo-piperidin wandelt sich in 30%iger Schwefelsaure haupt-sachlich in 1 -Methyl-2-propyl-pyrrolidin um (an Cd bei 60°, 41% d.Th.). Daneben entste-hen an anderen Kathoden zusatzlich Methyl-heptyl-amin bzw. an Kupfer l-Methyl-2-pro-pyl-4,5-dihydro-pyrrol1 ... 

The enantioselectivity of Sn(II) enolate reactions can be controlled by chiral diamine additives. These reagents are particularly effective for silyl thioketene acetals.162 Several diamines derived from proline have been explored and l-methyl-2-(l-piperidinomethyl)pyrrolidine 21 is an example. Even higher enantioselectivity can be achieved by attachment of bicyclic amines to the pyrrolidinomethyl group.163... 

Asymmetric sulfenylation. In the presence of the chiral diamine (S)-l-methyl-2-(piperidinylmethyl)pyrrolidine (1), tin(II) enolates of ketones react with... 

We now consider 7V-methyl-2-(3-pyridyl)pyrrolidine (7), also known as the alkaloid nicotine. Parallelling our discussion of coniine, we find in Kharasch and Domalski the nearly century-old enthalpy of formation for the liquid of 39 kJmol-1. Is this value plausible With (liquid, tert/R, R1, R2) necessary to transform a tertiary amine into the corresponding hydrocarbon24, we would conclude that the enthalpy of formation of liquid l-methyl-2-(3-pyridyl)cyclopentane (8, R = 3-Py) is ca —50 kJmol-1. To estimate the last datum in another way, we assume that equation 10 is essentially thermoneutral. 

Cervinka has employed these reagents in the asymmetric reduction of im-monium salts (49,50) and imines (51). The reduction of 2-substituted jV-methyl-A -tetrahydropyridinium perchlorates (10) with (— )-menthol-LAH in ether or THF led to optically active piperidine derivatives (eq. [10]). The optical purity obtained for the Pr" derivative was 12%. In the case of R = Me and Pr" the configuration of the predominant enantiomer was shown to be S. The (-)-menthol-LAH reagent was similarly shown to reduce l-methyl-2-alkyl-A -di-hydropyrrolinium perchlorates (11) to optically active pyrrolidine derivatives (eq. [11]). The optical yield could be calculated only for R = CH2Ph, and was only 6% (/ enantiomer) obtained with a 1 1 (— )-menthoi-LAH reagent. With 2 1 or 3 1 molar ratios of menthol LAH, the optical yield decreased. The... 

Neutral aminyl radicals generated by anodic oxidation of lithium alkenyl amides undergo a stereoselective cyclization to cis-l-methyl-2,5-disubstituted pyrrolidines [249]. 

On the other hand, the method of Mukaiyama can be succesfully applied to silyl enol ethers of acetic and propionic acid derivatives. For example, perfect stereochemical control is attained in the reaction of silyl enol ether of 5-ethyl propanethioate with several aldehydes including aromatic, aliphatic and a,j5-unsaturated aldehydes, with syir.anti ratios of 100 0 and an ee >98%, provided that a polar solvent, such as propionitrile, and the "slow addition procedure " are used. Thus, a typical experimental procedure is as follows [32e] to a solution of tin(II) triflate (0.08 mmol, 20 mol%) in propionitrile (1 ml) was added (5)-l-methyl-2-[(iV-l-naphthylamino)methyl]pyrrolidine (97b. 0.088 mmol) in propionitrile (1 ml). The mixture was cooled at -78 °C, then a mixture of silyl enol ether of 5-ethyl propanethioate (99, 0.44 mmol) and an aldehyde (0.4 mmol) was slowly added to this solution over a period of 3 h, and the mixture stirred for a further 2 h. After work-up the aldol adduct was isolated as the corresponding trimethylsilyl ether. Most probably the catalytic cycle is that shown in Scheme 9.30. 

Nicotine Nicotine, l-methyl-2-(3-piridyl)pirrolidine (13.1.27), is an alkaloid that is isolated from the plant Nicotiana (Nicotiana tabacum, Nicotiam rustica, and others) and can be synthesized in varions ways [33-36]. In particular, it is proposed to proceed from nicotinic acid ethyl ester, which is condensed with iV-methylpyrrolidone, giving l-methyl-2-nicotinoyl pyrrolidone-2 (13.1.23). Acidic hydrolysis of this compound leads to an opening of the pyrrolidine ring giving the intermediate (13.1.24), which under the reaction conditions is decarboxylated to the /-aminoketone (13.1.25). The carbonyl group is reduced to an alcohol and the resnlting prodnct (13.1.26) undergoes dehydration to nicotine (13.1.27). 

Methoxymethyl-l- (15)-2-niethoxy-l-methyl-2,5-cyclohcxadicnyl carbonyl pyrrolidine (7)32 ... 

NICOTINE 1-Methyl-2-(3-pyrldyl) pyrrolidine, J-(l-Methyl-2-pyrrolldyl) pyridine Poisonous, Class B, II 4 1 0... 

Nicotinoids. Nicotine from tobacco was one of the earliest insecticides and was recommended for use in 1763 as a tea for the destruction of aphids (1,20). Nicotine [54-11 -3], L-l-methyl-2-(3 -pyridyl)pyrrolidine (1) (bp 247°C, d 1.009), is found in the leaves of Nicotiana tobacum and N. rustica (Solanaceae) in amounts ranging from 2 to 14%, and also is found in Duboisia hopwoodii and in Aesclepias syriaca. It occurs as the principal alkaloid along with small amounts of 12 other alkaloids of which nomicotine [494-97-3], 2-(3,-pyridyl)pyrrolidine (2) (bp 270°C, d 1.07 g/mL), and anabasine [494-52-0], l-2-(3 -pyridyl)piperidiae (3) (bp 281°C, d 1.048), are of insecticidal importance (see Alkaloids). Nomicotine occurs as both the D and L forms, the former in D. hopn oodii and the latter commonly predominating in Nicotiana. Anabasine is the chief alkaloid of Anabasis aphylla, where it occurs from 1—2% in the shoots and is found to ca 1% in Nicotianaglauca. 

Aminyl radicals also can be generated via electrochemical oxidation of amide bases or O-substituted hydroxylamines. Suginome has studied radical cyclizations involving oxidations of lithium alkenylamides as a route to ccs-l-methyl-2,5-disubstituted pyrrolidines (85TL6085). Electrolysis of lithium alkenylamide 17a, generated from the amine and butyllithium at - 78°C, led to the formation of 18a, exclusively cis, in 52% yield (Scheme 4). The reactions require 0.25 M UC104 in THF HMPA (30 1) as the supporting electrolyte. A variety of 2-substituted amines were studied. 

Two examples of such situations are sketched in Scheme 1.11. Quatemization of tropane occurs mainly from the less hindered pyrrolidine side (equatorial attack at the piperidine ring), even though the main conformer of tropane has an equatorial methyl group. Similarly, l-methyl-2-phenylpyrrolidine yields mainly an anti alkylated product via alkylation of the minor cis conformer when treated with phenacyl bromide [33], In both instances the less stable conformer is more reactive to such an extent that the major product of the reaction results from this minor conformer. A further notable example of a reaction in which the main product results from a minor but more reactive intermediate is the enantioselective hydrogenation of a-acetamidocinnamates with a chiral rhodium-based catalyst [34],... 

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