- Small-Molecule Investigation of Diels-Alder Complexes for Thermoreversible Crosslinking in Polymeric Applications
-
Combinations of dienes and dienophiles were examined in order to elicit possible combinations for thermoreversible crosslinking units. Comparison of experimental results and quantum calculations indicated that reaction kinetics and activation energy were much better prediction factors than change in enthalpy for the prediction of successful cycloaddition. Further testing on diene-dienophile pairs that underwent successful cycloaddition determined the feasibility of thermoreversibility/retro-reaction of each of the Diels-Alder compounds. Heating and testing of the compounds in the presence of a trapping agent allowed for experimental determination of reverse kinetics and activation energy for the retro-reaction. The experimental values were in good agreement with quantum calculations. The combination of chemical calculations with experimental results provided a strong insight into the structure-property relationships and how quantum calculations can be used to examine the feasibility of the thermoreversibility of new Diels-Alder complexes in potential polymer systems or to fine-tune thermoreversible Diels-Alder systems already in use.
- Rowlett, Jarrett R.,Deglmann, Peter,Sprafke, Johannes,Roy, Nabarun,Mülhaupt, Rolf,Bruchmann, Bernd
-
p. 8933 - 8944
(2021/07/20)
-
- Application of maleimide compound as chitin synthase inhibitor
-
The invention discloses an application of a maleimide compound as shown in a formula I. In the formula I, R0 is phenyl, benzyl, phenethyl, phenylpropyl, p-fluorophenyl, p-chlorophenyl, p-bromophenyl,p-methoxyphenyl, p-methylphenyl or p-hydroxyphenyl, R1 is hydrogen, methyl, phenyl or chlorine; and R2 is hydrogen, methyl, phenyl or chlorine. The provided maleimide compound has a good inhibition effect on chitin synthase.
- -
-
Paragraph 0024-0027; 0040-0043
(2020/07/12)
-
- Synthesis of Tetrahydroisoindolinones via a Metal-Free Dehydrogenative Diels-Alder Reaction
-
A metal-free dehydrogenative Diels-Alder reaction of substituted alkenes for the synthesis of tetrahydroisoindolinones has been exploited for the first time. This new method features functional group tolerance and broad substrate scope, providing an efficient access to biologically active tetrahydroisoindolinone skeletons with endo steroselectivity in good to excellent yields. (Figure presented.).
- Xu, Wen-Lei,Tang, Lei,Ge, Chen-Yu,Chen, Jie,Zhou, Ling
-
supporting information
p. 2268 - 2273
(2019/04/10)
-
- Ru-Catalyzed Selective C-H Bond Hydroxylation of Cyclic Imides
-
We report on cyclic imides as weak directing groups for selective monohydroxylation reactions using ruthenium catalysis. Whereas acyclic amides are known to promote the hydroxylation of the C(sp2)-H bond enabling five-membered ring ruthenacycle intermediates, the cyclic imides studied herein enabled the hydroxylation of the C(sp2)-H bond via larger six-membered ruthenacycle intermediates. Furthermore, monohydroxylated products were exclusively obtained (even in the presence of overstoichiometric amounts of reagents), which was rationalized by the difficulty to accommodate coplanar intermediates once the first hydroxyl group was introduced into the substrate. The same reactivity was observed in the presence of palladium catalysts.
- Yuan, Yu-Chao,Bruneau, Christian,Dorcet, Vincent,Roisnel, Thierry,Gramage-Doria, Rafael
-
p. 1898 - 1907
(2019/02/05)
-
- Unmasking Amides: Ruthenium-Catalyzed Protodecarbonylation of N-Substituted Phthalimide Derivatives
-
The unprecedented transformation of a wide range of synthetically appealing phthalimides into amides in a single-step operation has been achieved in high yields and short reaction times using a ruthenium catalyst. Mechanistic studies revealed a unique, homogeneous pathway involving five-membered ring opening and CO2 release with water being the source of protons.
- Yuan, Yu-Chao,Kamaraj, Raghu,Bruneau, Christian,Labasque, Thierry,Roisnel, Thierry,Gramage-Doria, Rafael
-
supporting information
p. 6404 - 6407
(2017/12/08)
-
- Ruthenium(II)-Catalyzed C-H Activation with Isocyanates: A Versatile Route to Phthalimides
-
A cationic ruthenium(II)-complex was utilized in the efficient synthesis of phthalimide derivatives by C- H activation with synthetically useful amides. The reaction proceeded through a mechanistically unique insertion of a cycloruthenated species into a C- Het multiple bond of isocyanate. The novel method also proved applicable for the synthesis of heteroaromatic unsymmetric diamides as well as a potent COX-2 enzyme inhibitor. A convenient route to phthalimide: A convergent method for the ruthenium(II)-catalyzed imidation of easily accessible benzamides by C- H functionalization was developed (see scheme). The methodology was successfully applied to the preparation of synthetically challenging unsymmetrical heteroaromatic diamides and proved amenable to a step-economic synthesis of a potent COX-2 enzyme inhibitor.
- Desarkar, Suman,Ackermann, Lutz
-
supporting information
p. 13932 - 13936
(2016/02/18)
-
- Hydrogenations without hydrogen: Titania photocatalyzed reductions of maleimides and aldehydes
-
A mild procedure for the reduction of electron-deficient alkenes and carbonyl compounds is described. UVA irradiations of substituted maleimides with dispersions of titania (Aeroxide P25) in methanol/acetonitrile (1:9) solvent under dry anoxic conditions led to hydrogenation and production of the corresponding succinimides. Aromatic and heteroaromatic aldehydes were reduced to primary alcohols in similar titania photocatalyzed reactions. A mechanism is proposed which involves two proton-coupled electron transfers to the substrates at the titania surface.
- Manley, David W.,Buzzetti, Luca,MacKessack-Leitch, Andrew,Walton, John C.
-
p. 15324 - 15338
(2015/01/16)
-
- Synthesis, characterization, and computational study of potential itaconimide-based initiators for atom transfer radical polymerization
-
Atom transfer radical polymerization (ATRP) has been a promising technique to provide polymers with well-defined composition, architecture, and functionality. In most of the ATRP processes, alkyl halides are used as an initiator. We report the synthesis o
- Deoghare, Chetana,Baby,Nadkarni, Vishnu S.,Behera, Raghu Nath,Chauhan, Rashmi
-
p. 48163 - 48176
(2015/01/08)
-
- Substituent effects on the regioselectivity of maleamic acid formation and hydrogen chloride addition to N-aryl maleimides
-
Itaconic anhydride reacts with aryl amines to give a substituent controlled equilibrium mixture of regioisomeric (Z)-2-methyl- and (Z)-3-methyl-4-oxo-4- (arylamino)but-2-enoic acids. Electron-donating groups favor nucleophilic attack on C-5 carbonyl, while the presence of electron-withdrawing groups enhances the bias for attack on C-2 carbonyl. The treatment of (Z)-2-methyl- and (Z)-3-methyl-4-oxo-4-(arylamino)but-2-enoic acids with SOCl2-Et 3N in THF provided the corresponding maleimides in high yields while under the same conditions the maleic anhydride aryl amine addition products gave predominately the corresponding 3-chloro-1-arylpyrrolidine-2,5-diones and maleimides in substituent dependent ratio. TUeBITAK, 2012.
- Faturaci, Yeliz,Coskun, Necdet
-
p. 749 - 758
(2013/02/25)
-
- Solid-state photochemistry of crystalline pyrazolines: Reliable generation and reactivity control of 1,3-biradicals and their potential for the green chemistry synthesis of substituted cyclopropanes
-
To expand on the limited number of examples that exist in the literature for the solid-state photodenitrogenation of azoalkanes, a series of crystalline 7-alkyl-2,3,7-triazabicyclo[3.3.0]oct-2-ene-6,8-diones with varying 4,4-substituents were prepared. Th
- Shiraki, Saori,Vogelsberg, Cortnie S.,Garcia-Garibay, Miguel A.
-
p. 1929 - 1937
(2013/01/16)
-
- Synthesis and in vitro evaluation of N-substituted maleimide derivatives as selective monoglyceride lipase inhibitors
-
The endocannabinoid 2-arachidonoylglycerol (2-AG) plays a major role in many physiological processes, and its action is quickly terminated via enzymatic hydrolysis catalyzed by monoglyceride lipase (MGL). Regulating its endogenous level could offer therapeutic opportunities; however, few selective MGL inhibitors have been described so far. Here, we describe the synthesis of N-substituted maleimides and their pharmacological evaluation on the recombinant human fatty acid amide hydrolase (FAAH) and on the purified human MGL. A few N-arylmaleimides were previously described (Saario, S. M.; Salo, O. M.; Nevalainen, T.; Poso, A.; Laitinen, J. T.; Jarvinen, T.; Niemi, R. Characterization of the Sulfhydryl-Sensitive Site in the Enzyme Responsible for Hydrolysis of 2-Arachidonoylglycerol in Rat Cerebellar Membranes. Chem. Biol. 2005, 12, 649-656) as MGL inhibitors, and along these lines, we present a new set of maleimide derivatives that showed low micromolar IC50 and high selectivity toward MGL vs FAAH. Then, structure-activity relationships have been investigated and, for instance, 1-biphenyl-4-ylmethylmaleimide inhibits MGL with an IC50 value of 790 nM. Furthermore, rapid dilution experiments reveal that these compounds act as irreversible inhibitors. In conclusion, N-substituted maleimides constitute a promising class of potent and selective MGL inhibitors.
- Matuszak, Nicolas,Muccioli, Giulio G.,Labar, Geoffray,Lambert, Didier M.
-
experimental part
p. 7410 - 7420
(2010/04/30)
-
- Succinimide and maleimide derivatives and their use as topoisomerase II catalytic inhibitors
-
Maleimide and succinimide derivatives were found to be effective topoisomerase II catalytic inhibitors. Due to this property, the maleimide and succinimide derivatives were investigated for their use as cytostatic agents and thus in the treatment of cancer. The compounds of the invention can be used in combination treatments with other cytostatic agents, such as topoisomerase II poisons. The maleimide and succinimide derivatives, due to their effective topoisomerase II catalytic inhibitory activity, are also useful as extravasation agents, such as upon administration of a topoisomerase II poison.
- -
-
-
- Revised Structures of N-Substituted Dibrominated Pyrrole Derivatives and Their Polymeric Products. Termaleimide Models with Low Optical Band Gaps
-
This paper describes an unexpected rearrangement/oxidation of N-substituted 2,5-dibromopyrroles upon treatment with HNO3. The bromides migrate from the 2,5-positions to the 3,4-positions with subsequent oxidation at the 2,5-positions to afford N-substituted 3,4-dibromomaleimides; the structure was confirmed by single-crystal X-ray analysis. The maleimides were then polymerized to the poly(N-substituted-3,4-maleimide)s with copper bronze. This constitutes a revision of structure for the monomers and polymers. The propensity for the dibromide migration was further confirmed by treatment of N-benzyl-2,5-dibromopyrrole under nonoxidative acidic conditions (p-TsOH) to afford N-benzyl-3,4-dibromopyrrole; both the starting material and product structures were confirmed by single-crystal X-ray analysis. Several termaleimides were prepared from pyrrole, maleic anhydride, and citraconic anhydride. These trimeric compounds underwent enormous shifts in their optical absorbance maxima (ca. 200 nm) when bases or nucleophilic solvents were added. Therefore, the termaleimides served as excellent models for the polymeric systems that had undergone shifts of 350-400 nm upon treatment with the same additives. Ab initio Hartree-Fock and density functional theory were utilized to assess the minimum conformation of the trimeric system. Both terminal maleimides appear canted 37° relative to the central maleimide unit. As the two end maleimide units were computationally forced into closer proximity, there was a dipolar stabilization that ensued between the two terminal maleimides with the formation of a 1,3-dioxetane. However, it is unlikely that there could be the formation of an isolable 1,3-dioxetane due to the large energy difference between the canted structure and the dioxetane. A significant decrease in the HOMO-LUMO energy of 13 kcal/mol was calculated upon formation of the 1,3-dioxetane, suggesting that nucleophiles likely move the canted structure more toward a planar form via addition to the α,β-unsaturated carbonyl units.
- Choi, Dong-Sook,Huang, Shenlin,Huang, Mingsheng,Barnard, Thomas S.,Adams, Richard D.,Seminario, Jorge M.,Tour, James M.
-
p. 2646 - 2655
(2007/10/03)
-
- Product diversity in cyclisations of maleamic acids: The imide-isoimide dichotomy
-
Cyclisation of maleamic acids with acetic anhydride in dimethylacetamide (DMA) at ca. 75°C, with or without added cobalt naphthenate, gives predominantly maleimides when the parent maleic anhydride is unsubstituted. However, when the maleic anhydride has
- Corrie, John E. T.,Moore, Madeleine H.,Wilson, Giles D.
-
p. 777 - 781
(2007/10/03)
-
- Cumulated Ylides, XVII. Synthesis of Cyclic Compounds from Triphenylphosphorane and Oxocarboxylic Acids - A Novel Method for Anellation
-
By entropically supported intramolecular Wittig reaction from α-keto carboxylic acids 23 with triphenylphosphorane (1) N-phenylmaleinisoimides 26 and -imides 29 are formed.The compounds 26 can be rearranged into 29 with a catalytic amount of sodium azide. - From γ-keto carboxylic acids 30 3-substituted 2-cyclopenten-1-ones 37 can be derived via the 3,6-dioxo-2-(triphenylphosphoranylidene)alkananilides 33.Analogously, 3-substituted 2-cyclohexen-1-ones 49 are formed from δ-keto carboxylic acids 46. o-Acylbenzoic acids 38, in the case R = H, are converted with 1 into the benzazepinedione derivative 44, and in the case R unlike H into 3-substituted 1-oxo-1H-indene-2-carboxanilides 45. - Starting from oxo carboxylic acids, possessing the carbonyl function in a ring, five- and six-membered rings can be anellated in a simple way.
- Bestmann, Hans Juergen,Schade, Gerold,Luetke, Harry,Moenius, Thomas
-
p. 2640 - 2658
(2007/10/02)
-
- Thermolysis of 7-Phenyl-2,3,7-triazabicyclooct-2-ene-6,8-dione
-
Thermolysis of the title compound in boiling xylene (138 deg) produces a 7.7/10.1/1.0 mixture of the N-phenylimides of cis-1,2-cyclopropanedicarboxylic acid, citraconic acid, and itaconic acid.The imides of citraconic and itaconic acids are produced by hydrogen shifts.A completely concerted mechanism involving simultaneous hydrogen shift and cleavage of both C-N bonds is unlikely in the present case because both hydride-shift products are formed and because the optimal arrangement for the hydrogen shift requires deformation of the imide ring and loss of imide resonance.The C-N bond strengths in the title compound should be quite different.The products can arise either from two parallel pathways involving nitrogen-containing dipoles or from a single nitrogen-free trimethylene fragment.
- Majchrzak, Michael W.,Kotelko, Antoni
-
p. 1475 - 1477
(2007/10/02)
-
- NEW C-C BOND FORMATION WITH PYRIDINIUM METHYLIDE: HYDROMETHYLENATION OF OLEFIN
-
New C-C bond formation with pyridinium methylide is presented: Pyridinium methylide reacts with electron-deficient olefins providing the next higher homologs of olefins, in which the double bond of starting olefin is saturated and, instead, a C=C double bond is newly formed.This reaction mode has been never reported before in the study of nitrogen ylide and is to be referred to as hydromethylenation of olefin.In the presence of base, 1,2-double bond migration occurs leading to the methylated derivatives of starting olefins.
- Tsuge, Otohiko,Kanemasa, Shuji,Kuraoka, Satoru,Takenaka, Shigeori
-
p. 281 - 284
(2007/10/02)
-