N-methyl maleimide

The unusual annulation of a substituted phenyl ring through [4 + 2] cycloaddition of vinyl compound 59 with dimethyl acetylenedicarboxylate (DMAD) as dienophile affords indolo benzazepine 60 in 53% yield, while a similar reaction with N-methyl-maleimide or maleic anhydride yields tetracyclic 61a,b in 53-87% yield (Scheme 12 (2003T6659)). 

An exhaustive series of reports by Grigg et al. (28) outlined two basic methods for the generation of azomethine ylides proceeding via either a 1,2-prototropic shift, or by a decarboxylative approach (29). The decarboxylative route to azomethine ylides can be exemplified by the condensation of benzaldehyde with the cyclic amino acid tetrahydroisoquinoline (108) (30), in DMF at 120 °C, to generate the intermediate awfi-dipole 109, which underwent subsequent cycloaddition with N-methyl maleimide to furnish a 1 1 endo/exo mixture of adducts 110 (R = Ph), in 82% yield (Scheme 3.30). 

Signal transduction was studied most precisely for the 5-HTiA receptor in rat amygdala (Koyama et al. 1999). The receptor operated through a N-methyl maleimide-sensitive mechanism and by adenyl cyclase inhibition rather than any change in K+ or Ca2+ channels. The fall in cyclic AMP presumably was followed by decrease in the phosphorylation of synaptic vesicle proteins and, finally, in a decrease of exocytosis. 

The indole[2,3-a]carbazole 185 possessing the rebeccamycin aglycone unit [122-132,135,136] was synthesized from the reaction of N-methyl-maleimide and 2,2/-bisindolyl 181 via Michael type addition. In the presence of aluminum trichloride, the bisindole reacts to form the Michael adducts 182 and 183. The mono-Michael adduct 182 was dehydrogenated in the presence of Pd/C in a one pot procedure to produce 184 and 185 (Scheme 43) [ 137]. 

Thiophene containing fused 6, 7 and 8 membered ring systems 41-46 have been prepared from in situ generated azomethine imines followed by cycloaddition to N-methyl maleimide and subsequent Pd(0) catalyzed cyclizations <03T(59)4451>. 

Figure 7.18. The cleavage of metal-metal bonds with 1, 2-6/5(diphenylphosphino)-N-methyl-maleimide.

Other compounds reacting similarly via activated double bonds (excluding here block or graft copolymerization) include maleic acid, N-methyl-maleimide, chloromaleic anhydride, fumaric acid, 7-crotonolactone, p-benzoquinone, and acrylonitrile. Other polymers with unsaturated backbones, such as polybutadiene, copolymers of butadiene with styrene and with acrylonitrile, and butyl rubber, react in similar ways, but the recorded reaction with poly(vinyl chloride) is largely mechanochemical in nature (discussed later). 

In 2012, Keglevich and coworkers reported the catalyst-free synthesis of a series of new >P(0)-substituted maleic derivatives (62) via microwave-assisted phospha-Michael addition of diall l phosphites, ethyl phenyl-H-phosphinate, and diphenylphosphine oxide to Al-phenyl and N-methyl maleimide (61), in most of the cases without any solvent, in good yields (71-98%) and within 3 h (Scheme 29). This method is advantageous over the previously reported method of Jiang et al. in terms of using no solvent or catalyst. 

In the reaction of fused aziridines with alkene dipolarophiles, the opportunity for stereoselectivity as well as facial selectivity arises since exo- or entfo-isomers can be formed (Scheme 10). In practice, maleic anhydride 6, A-methyl maleimide and JV-phenyl maleimide each reacted exo-stereoselectively with TV-benzyl aziridine 69 to form adducts of type 71 (Scheme 10b), the stereochemistries of which were confirmed by NOE measurement between Hb and He. Similar reaction of the Y-phenyl aziridine 67 with N-Ph maleimide gave a 1 1 mixture of endo-adduct 72 and exo-adduct 73 (Scheme 10c). Adducts 68, 71-73 all exhibited a low-field methano-bridge proton (Ha) in the range 5 3.06-3.60 confirming the syn-facial stereochemistry of the two bridges. 

Scheme 1.64). The Ag(I)-mediated cyclization afforded dipole 306 for 1,3-dipolar cycloaddition with methyl vinyl ketone to yield adducts 307 and the C(2) epimer as a 1 1 mixture (48%). Hydrogenolytic N—O cleavage and simultaneous intramolecular reductive amination of the pendant ketone of the former dipolarophile afforded a mixture of alcohol 308 and the C(6) epimer. Oxidation to a single ketone was followed by carbonyl removal by conversion to the dithiolane and desulfurization with Raney nickel to afford the target compound 305 (299). By this methodology, a seven-membered nitrone (309) was prepared for a dipolar cycloaddition reaction with Al-methyl maleimide or styrene (301). 

Among photooxidation products of the betaines 86 (R = Me, PhCH2, Ph, = H) are N-substituted maleimides (107). Evidence for the intermediate 108 in these reactions is provided by the observation that photooxidation of l-methyl-5-phenylpyridinium-3-olate (86 R = Me, R = Ph) gives the peroxy dimer 109 (11%). ... 

The Diels-Alder reaction of pyrrole-3-carboxyhc esters with TV-methyl- and N-phenyl-maleimides yield exclusively endo adducts.243 The Diels-Alder reaction of... 

CMIMX Methyl methacrylate-co-N-cydohexyl maleimide copolymer containing x molar percent of the latter comonomer... 

Methyl Methacrylate-co-N-cydohexyl Maleimide Random Copolymers. . 267... 

Keywords Mechanical properties Plastic deformation Poly(methyl methacrylate) Methyl methacrylate-co-N-cyclohexyl maleimide copolymer ... 

The structure of the methyl methacrylate-co-N-cyclohexyl maleimide copolymers is shown in Fig. 33. The maleimide cycle is a rigid structure whose C - C bond contributes to the chain backbone. 

More or less similar behavior has been observed (8) in the blends of the copolymer or the terpolymer with the following bis-A polycarbonate, polyvinyl chloride, poly (ethyl methacrylate), and a terpolymer made from methyl methacrylate, N,N -dimethyl acrylamide, and N-phenyl-maleimide. Because of this unique miscibility characteristic of the a-methyl styrene interpolymers, an attempt was made at compati-bilizing polyarylethers with the interpolymers by attaching pendant chemical groups known to exist in systems with which the interpolymers are miscible. 

PMVPD PNA POD PODMI POEDE poly(2-methyl-5-vinylpyridine) polylsodium acrylate) polyoctadecene-1 poly(N-(n-octadecyl)maleimide) poly(oxyethylene)dodecyl ether... 

The generation of the carbcxi-carbon double bond of unsaturated nitrogen heterocycles by the rDA reaction of cycloadducts that act as protected ethylenes has been accomplished. Azetines have been prepared by this method. Another example is the synthesis of l-methyl-3-pyrroline (201). By protecting the ethylene of N-methylmaleimide (199) with furan and then reducing with lithium aluminum hydride, adduct (200) was obtained (equation 86). Pyrolysis of adduct (200) at 250-300 C gave l-methyl-3-pyrroline (201) in 60% isolated yield. The ethylene moiety of N-substituted maleimides can also be generated via rDA reactions. Examples include the generation of N-phenylmaleimide (equation 87) and of N-acetoxymaleimide (equation 88). ... 

Inhib. abbrev. DTT = dithioghreitol E64D = epoxysuccinyl-L-leucyl-amido-3-methyl-butane ethyl ester EDTA = ethylene-diamine-tetra-acetic acid EGTA = ethylen-glycol-tetra-acetic acid LHVS = morpholinurea-leucine-homophenyl-alanine-vinylsulfone-phenyl NEM = N-ethyl-maleimide PAI = plasminogen activator inhib. PMSF = phenil-methyl-sulfonil fluoride SBTl = soybean trypsin inhib. TIMP = tissue inhib. of metalloproteinases TPCK = tosyl-L-phenyl-alanyl-chloro-methane Al.so termed stephins. 

Fig. 2. Accumulation of medicarpin in Ladino clover callus elicited with N-ethyl maleimide. Data are from three separate experiments. 1) Callus was prepared as described (19) and divided into vials containing the indicated concentrations of NEM (one vial for each NEM concentration). After 24-hour incubation period, callus was extracted with methyl ethyl ketone, and medicarpin concentrations determined in the extracts by HPLC (19) - . 2) Same as experiment 1,...

In 1960, Natta reported the first direct synthesis of an optically active polymer from an achiral monomer, where methyl sorbate was polymerized using (R)-2-pentyllithium [95]. Ozonolysis of the polymer (under conditions possibly allowing epimerization) produced (S)-methyl succinic acid in 5% ee, which provides evidence of asymmetric induction and absolute configuration of the polymer main chain. Since this initial report, a remarkable void in the Hterature exists concerning the synthesis of main-chain chiral polymers from achiral monomers using anionic initiators. Okamoto and Oishi have polymerized N-substituted maleimides with chiral anionic initiators (Scheme 14) [96,97]. The polymer is assumed to have predominantly a frans-diisotactic microstructuxe, which adopts a secondary helical structure. The absolute configuration of the main chain has... 

Figure 2.4. Schematic illustrations of repeat units of several of the polymers listed in Table 2.2. (a) Poly(thiocarbonyl fluoride), (b) Poly(glycolic acid), (c) Polyepichlorohydrin. (d) Poly(maleic anhydride), (e) Poly(N-methyl glutarimide). (f) Poly(N-phenyl maleimide). (g) Poly[3,5-(4-phenyl-1,2,4-triazole)-1,4-phenylene]. (h) Phenoxy resin, (i) Poly(oxy-1,4-phenylene-oxy-1,4-phenylene-carbonyl-l,4-phenylene). (j) Udel. (k) Victrex. (1) Tori on. (m) Ultem. (n) Resin F.

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