Olefin imidazolines

Napamezole (68) is a dihydroimidazole derivative with antidepressant activity probably as a result of its combined a 2 adrenergic receptor blockuig and serotonin uptake blocking proper ties It can be synthesized by Wittig olefination of p-tetralone (65) with diethyl (cyanomethyl) phosphonate (66) and base to give nitnle 67 Imidazoline construction on the latter was smoothly... 

The high enantioselectivity again can be rationalized by enantioface-selective alkene coordination in 63 (Fig. 35). The olefin moiety is expected to bind trans to the upper imidazoline moiety [70,73] thereby releasing the catalyst strain. Coordination at this position may, in principal, afford four different isomers assuming the stereoelectronically preferred perpendicular orientation of the alkene and the Pt(II) square plane. In the coordination mode shown, steric repulsion between both olefin substituents and the ferrocene moiety is minimized. Outer-sphere attack of the indole core results in the formation of the product s stereocenter. 

Thermolysis of a stable radical 4-[(hydroxyimino)nitromethyl]-2,2,5,5-tetra-methyl-3-imidazolin-l-oxyl 13 gives the corresponding spin-labeled nitrile oxide. It was also identified in isoxazolines formed in cycloadditions with olefins (88). 

The development of chiral hydrogenation catalysts for unfunctionalized alkenes also allows enantioselective hydrogenation of functionalized olefins where the functionality in the molecule is remote from the double bond. A series of oxazoline-, imidazoline- and pyridine-derived catalysts have been screened for the hydrogenation of unsaturated derivatives of vitamin E (Scheme 30.3). Hy-... 

M. Scholl, T. M. Trnka, J. P. Morgan, and R. H. Grubbs, Increased Ring Closing Metathesis Activity of Ruthenium-Based Olefin Metathesis Catalysts Coordinated with Imidazolin-2-ylidene Ligands, Tetrahedron Lett. 1999, 2247-2250. 

A direct and efficient route to imidazoline and pyrrolidine derivatives using copper(ll) triflate-mediated [3+2] cycloaddition of various aryl, alkyl, and cycloalkyl iV-tosylaziridines with nitriles and olefins as dipolarophiles has been reported <2006TL5399>. Formation of bicyclic imidazoline 334 with a /ra j-ring junction as a single product from aziridine 333 suggested that the reaction proceeded through an SN2-type pathway (Scheme 86). 

The oxidation of 4-imidazolin-2-selones with 7,7,8,8-tetracyanoquinodime-thane [96] and electrochemical oxidation of benzthiazoline-2(3H)-selone has been carried out [97]. The properties of the former products have also been tested as semi-conducting molecules. The elimination of selenocarboxyl groups and sulfonyl groups mediated by JV-acyloxypyridinethione gives olefins (Eq. 26) [98]. 

Amidinyl radicals 1166 are readily generated from amidoxime benzoates, for example, 1165, by treatment with a stannane-diazo initiator or with Ni-AcOH and captured by an internal olefin to give the corresponding imidazoline 1167. Interestingly, the use of allyl tri- -butylstannane in the case of substrate 1168 results in the clean formation of allyl imidazoline 1169. As expected, allylation occurs from the least hindered exo face to give the isomer shown (Scheme 284) <2003CC1870> (ACCN = l,l -azobis(cyclohexanecarbonitrile)). 

Because of their predictable behavior and reactivity, thioacyl isocyanates comprise the bulk of this work, and extensive studies of their [4 + 2] reactions with olefins,83 enamines,84 enol ethers,843 thioacyl isocyanates,85 imines,85 1 86 carbodiimides,84387 isocyanates,843 azirines,88 /3-enaminoke-tones,89 dianils,86d azines,90 hydrazones,91 imidazoline-4,5-diones,92 aryl cyanates,93 disubstituted cyanamides,93 aldehydes,94 ketones,94 ketenes,94 alkyl or aryl iminodithiocarbonates,95 and the carbon-carbon double bond of ketenimines96 have been detailed. In an extensive comparative study of the [4 + 2] cycloaddition reactions of thioacyl isocyanates, the heterocu-mulenes bearing strong electron-withdrawing substituents were found to be more stable and less prone to participate in cycloaddition reactions.84 Representative examples are summarized in Scheme 9-IV. 

PEG-7 tallow aminopropylamine PEG-12 tallow aminopropylamine Poloxamer 217 Propylene glycol myristate Sodium dodecylbenzenesulfonate Sodium 2-ethylhexyl sulfate Sodium nonoxynol-4 sulfate Tall oil hydroxyethyl imidazoline Trideceth-6 Trideceth-12 detergent, paints/coatings Cl 2-14 pareth-8 Cl 2-15 pareth-7 Cl 3-15 pareth-20 Cl 4-15 pareth-7 Nonoxynol-60 Octoxynol-1 Octoxynol-3 Octoxynol-9 Octoxynol-16 PEG-25 stearamine PEG-40 stearamine Sodium C14-16 olefin sulfonate Sodium octyl sulfate Trideceth-15 detergent, paper... 

Sodium C4-12 olefin/maleic acid copolymer Sodium decyl sulfate Sodium polycarboxylate Sodium polymethacrylate Sodium polynaphthalene sulfonate Sodium tallate Soyamide DEA Stearamide Stearamine Styrene/MA copolymer Tall oil acid Tall oil hydroxyethyl imidazoline Tallow dipropylene triamine TEA-dodecylbenzenesulfonate Tricontanyl PVP Tridecyl neopentanoate Tridecyl trimellitate Triisocetyl citrate Trioctyidodecyl citrate dispersant, pigment dispersions Disodium decyl diphenyl ether disulfonate lsotrideceth-9 Octoxynol-11... 

Propylene glycol isoceteth-3 acetate Quaternium-52 Ricinoleamidopropyl ethyidimonium ethosulfate Sodium cetearyl sulfate Sodium C14-16 olefin sulfonate Sodium C12-15 pareth-8 carboxylate Sodium Cl 2-15 pareth-3 sulfonate Sodium Cl2-15 pareth-7 sulfonate Sodium Cl 2-15 pareth-15 sulfonate Sodium methyl cocoyl taurate Sodium trideceth sulfate Soyamide DEA Steapyrium chloride Stearamide MEA Stearamidopropyl dimethylamine Steareth-80 Stearyl phosphate Sucrose distearate Sucrose stearate TEA-dimethicone copolyol phosphate TIPA-lauryl sulfate , Undeceth-8 emulsifier, personal care cleansers C9-15 all l phosphate Disodium oleamido MIPA-sulfosuccinate emulsifier, personal care conditioning Dimethicone copolyol isostearate emulsifier, personal care soaps Sodium palmitate emulsifier, personal care mild Sodium laureth-13 carboxylate emulsifier, pesticide Trideceth-6 phosphate emulsifier, pesticide sprays PEG-9 dioleate emulsifier, pesticides Behenyl aminoethyl imidazoline Calcium dodecylbenzene sulfonate Cocoyl aminoethyl imidazoline Cocoyl sarcosine Dimethyl caproamide... 

Sodium a olefin sulfonate Stearyl hydroxyethyl imidazoline Stearyl methacrylate Tallow propylene diamine Trifluoromethane sulfonic acid Vinylidene chloride monomer Xylenol paints, aluminum Coumarone/indene resin paints, aluminum decorative/structure Coumarone/indene resin... 

SchoU, M., Trnka, T.M., Morgan, J.P. and Grubbs, R.H. (1999) Increased ring closing metathesis activity of ruthenium-based olefin metathesis catalysts coordinated with imidazolin-2-ylidene ligands. Tetrahedron Lett., 40, 2247-50. 

The synthesized zwitterionic iridium complexes containing various chiral P, N ligands with imidazoline or oxazoline were used as precatalysts for the asymmetric hydrogenation of unfunctionalized olefins. The cationic complexes with fluorinated borates as anions were superior catalysts in dichloromethane, whereas the iridium betaines were good catalysts in pure hydrocarbons. ... 

After having observed that the most active ruthenium-based catalyst systems for olefin metathesis also displayed a high efficiency in atom transfer radical polymerisation, we then became interested in comparing the role of the catalyst in those two different reaction pathways. Ruthenium alkylidene complexes 4-6 are unsaturated 16-electron species which formally allow carbon-halogen bond activation to form a 17-electron ruthenium(III) intermediate. Our preliminary results indicate that polymerisations occur through a pathway in which both tricyclohexylphosphine and/or imidazolin-2-ylidene ligands remain bound to the metal centre. 

In a few cases the formulae given above are oversimplified, in the sense that commercial materials contain other related compounds which may complicate their analysis. The complexity of a-olefin sulphonates has already been mentioned. With such mixtures, conversion of a titration volume to an active percentage is not straightforward, because it is debatable which constituents should be considered as actives, and the effective molecular weight is uncertain. A more complicated case is that of imidazoline and imidazolinium derivatives. The chemistry involved in the synthesis of these materials is very complex, and it seems likely that all the commercial materials contain a mixture of several different active structures [1,2]. 

Similar trends were observed for RCM to access disubstituted olefins. However, this reaction was faster if catalyzed by complex 55d rather than by 55b. The overall activities were excellent and reached values close to those obtained with the standard Grubbs II catalyst precursors. Formation of trisubstituted olefins was slower and the triazolylidene-based complexes underperformed classical imidazolin-2-ylidene systems used in the original Grubbs II catalyst. 

An alternative method of synthesizing 3-imidazoline-3-oxide nitroxides is oxidation with hydrogen peroxide of 2,2,5,5,-tetraalkyl-3-imidaz-oline-3-oxides (8) containing a sterically hindered secondary amino group (Martin and Volodarsky, 1979). Compounds 8 are derived from a-aminooximes generated from olefinic nitrosochlorides (Michael and... 

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