NHC‐Catalyzed Asymmetric Synthesis of Functionalized Succinimides from Enals and α‐Ketoamides

The efficient asymmetric synthesis of highly substituted succinimides from α,β‐unsaturated aldehydes and α‐ketoamides via NHC‐catalyzed [3+2] cycloaddition has been developed. The new scalable protocol significantly expands the utility of NHC catalysis for the synthesis of heterocycles and provides easy access to assemble a wide range of succinimides from simple starting materials.     

Die Massenspektren substituierter Succinimide

The mass spectra of succinimide, four monosubstituted and ten disubstituted saturated succinimides and six unsaturated ( = ethylidene substituted) succinimides are recorded and interpreted. Fragmentation schemes are derived which permit the identification of unknown substituted succinimides obtained by degradation of natural pyrrole pigments.     

A regioselective reduction of gem-disubstituted succinimides

The NaBH₄ reduction of mono- and disubstituted succinimides in the presence of hydrochloric acid leading to ω-carbinol-lactams shows a remarkable regio- and/or stereo-selectivity. The reduction takes place at the most substituted CO in the succinimides. Possible explanations are reviewed. The preparative value of the method is amply illustrated.     

Highly enantioselective α-sulfenylation of 5H-oxazol-4-ones to N-(sulfanyl)succinimides

An unprecedented asymmetric α-sulfenylation of 5H-oxazol-4-ones to N-(sulfanyl)succinimides has been established, to access various α-sulfenylated adducts with good to excellent enantioselectivities (86–95% ee) by utilizing a cinchona alkaloid-derived squaramide as catalyst. The conditions of this α-sulfenylation protocol simultaneously satisfy N-(arylthio)succinimides, N-(benzylthio)succinimides, and N-(alkylthio)succinimides by tuning the substituted groups of 5H-oxazol-4-ones on the 2-position as well as additives.     

环状酰亚胺不对称还原烷基化的一些结果

苹果酰亚胺的不对称还原烷基化是合成γ-内酰胺的有效方法,为扩大该法的应用范围,本文研究了多种环状酰亚胺的还原烷基化反应。探讨了影响还原烷基化反应的因素并提出相关的解释。总结出3-取代和3,4-二取代琥珀酰亚胺可成功地进行还原烷基化的规律,并提出了相应的解释。     

Bicyclic guanidine-catalyzed asymmetric Michael additions of 3-benzyl-substituted oxindoles to N-maleimides

A bicyclic guanidine-catalyzed Michael addition of 3-benzyl substituted oxindoles to N-maleimides has been developed to produce oxindole derivatives with a quaternary carbon chiral center at the 3-position in excellent yields and enantio- and diastereoselectivities. This is the first incorporation of N-benzylic α-branched succinimides into 3,3-disubstituted oxindoles.     

A convenient synthesis of 4-aminoaryl substituted cyclic imides

An efficient one-step synthesis of 4-nitro-N-aryl substituted glutarimides, succinimides and maleimides in polyphosphoric acid is described together with the subsequent reduction to the corresponding anilines. The scope and limitation of this cyclocondensation are presented.     

Synthesis,X-Ray Crystallography,and Reactions of N-Acyl and N-Carbamoyl Succinimides

A collection of N-acyl and N-carbamoyl succinimides were prepared by acylation of succinimide with acyl chlorides or by ethylene dichloride (EDC) coupling of carboxylic acids. The x-ray crystal structures of N-benzoyl and N-p-nitrobenzoyl succinimides were determined. The N-acyl succinimides were effective in acylating primary amines, a secondary amine, and an aromatic amine.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

l-Isoleucine-catalyzed Michael Synthesis of N-Alkylsuccinimide Derivatives and Their Antioxidant Activity Assessment

Russian Journal of Organic Chemistry - N-Substituted succinimides having different alkyl groups were prepared by the reaction of N-substituted maleimide with aldehydes. A two-component catalyst...     

Selective Ruthenium‐Catalyzed Reductive Alkoxylation and Amination of Cyclic Imides

Reported herein, for the first time, is the selective ruthenium‐catalyzed reductive alkoxylation and amination of phthalimides/succinimides. Notably, this novel methodology avoids hydrogenation of the aromatic ring and allows methoxylation of substituted imides with good to excellent selectivity for one of the carbonyl groups. The reported method opens the door to the development of new processes for the selective synthesis of various functionalized N‐heterocyclic compounds. As an example, intramolecular reductive couplings to afford tricyclic compounds are presented for the first time.     

Highly enantioselective reduction of the C–C double bond of N-phenyl-2-methyl- and N-phenyl-2,3-dimethyl- maleimides by fungal strains

The CC double bond of non-substituted and substituted maleimides were hydrogenated to the corresponding succinimides by fungal strains. 2- and 2,3-methylated-phenyl-maleimides were enantioselectively reduced to (R)-N-phenyl-3-methylsuccinimide and to trans-(R,R)-N-phenyl-2,3-dimethylsuccinimide respectively by Aspergillus niger, A. flavus and A. fumigatus (conversion 96 to 99%), Fusarium graminearum and Penicillium sp (conversion: 37 and 39%), with 99% ee.     

BF3 ⋅ Et2O-Mediated Annulation of 2-Alkynyl Biaryls with N-(Arylthio) Succinimides: An Efficient Approach to Access 9-Sulfenylphenanthrenes

A simple and effective method for the synthesis of 9-sulfenylphenanthrenes was developed via BF₃ ⋅ OEt₂-mediated annulation of 2-alkynyl biaryls with N-arylthio succinimides at room temperature. Through this methodology, a series of 9-sulfenylphenanthrenes could be efficiently and conveniently obtained in good to excellent yields under mild and metal-free conditions.     

Ring-Opening 1,3-Aminochalcogenation of Donor–Acceptor Cyclopropanes: A Three-Component Approach

A 1,3-aminothiolation was realized by reacting 2-substituted cyclopropane 1,1-dicarboxylates with sulfonamides and N-(arylthio)succinimides. Under Sn(OTf)₂ catalysis the transformation proceeded smoothly to the corresponding ring-opened products bearing the sulfonamide in the 1-position next to the donor and the arylthio residue in the 3-position next to the acceptor. The procedure was extended to the corresponding selenium analogues by employing N-(phenylseleno)succinimides as an electrophilic selenium source.     

Relationship between enantioselectivity and solute structure on a chiral α1-acid glycoprotein column

Summary The relationship between the enantioselectivity, the retention and the solute structure for N-aminoalkylsuccinimides and 1-alkyl-2′,6′-pipecoloxylidides have been studied using α₁-acid glycoprotein as the chiral stationary phase. Both the enantioselectivity and the retention are highly affected by small changes of the solute structure in series of homologous compounds. For example, increasing the steric bulk on a basic aliphatic nitrogen improves the enantioselectivity. It was also demonstrated for the succinimides that the magnitude of the separation factor was highly affected by the distance between the basic nitrogen and the chiral center. The chiral selectivity was not lost for the succinimides despite the fact that the basic nitrogen was separated from the chiral center with seven atoms, which may be an effect of that these compounds contain more than one strong hydrogen bonding group. Substitution in the aromatic ring of the succinimides also influences both the retention and the chiral selectivity to a large extent. Electronegative substituents can increase the separation factor but introduction of an alkyl or an alkoxy group in the aromatic ring decreases the enantioselectivity for the succinimides.     

An efficient synthesis of 3-(guaiazulene-1-yl)succinimides by addition of guaiazulene to maleimides

A facile,efficient synthesis of 3-(guaiazulen-1-yl)succinimides was developed by Michael-type addition of guaiazulene to maleimides in the presence of p-toluenesulfonic acid under mild reaction conditions.     

Direct organocatalytic synthesis of enantiopure succinimides from beta-lactam aldehydes through ring expansion promoted by azolium salt precatalysts

A single-step catalytic ring expansion approach from 4-oxoazetidine-2-carbaldehydes to enantiopure succinimides has been achieved by the use of a base (DBU) and a thiazolium salt precatalyst.     

Peptide-Catalyzed Stereoselective Conjugate Addition Reaction of Aldehydes to C-Substituted Maleimides

Catalytic stereoselective additions with maleimides are useful one-step reactions to yield chiral succinimides, molecules that are widespread among therapeutically active compounds but challenging to prepare when the maleimide is C-substituted. We present the tripeptide H-Pro-Pro-Asp-NHC₁₂H₂₅ as a catalyst for conjugate addition reactions between aldehydes and C-substituted maleimides to form succinimides with three contiguous stereogenic centers in high yields and stereoselectivities. The peptidic catalyst is so chemoselective that no protecting group is needed at the imide nitrogen of the maleimides. Derivatization of the succinimides was straightforward and provided access to chiral pyrrolidines, lactones, and lactams. Kinetic studies, including a Hammett plot, provided detailed insight into the reaction mechanism.     

Nucleophilic chain substitution on perfluoroketene dithioacetals by ethyl 2-trimethysilyl acetate. Application to the synthesis of 2-trifluoromethyl succinic acid derivatives

A highly efficient substitution of the vinyl fluoride of perfluoroketene dithioacetals was achieved using trimethylsilylacetate to give 2-perfluoroalkyl succinic acid derivatives and 2-trifluoromethyl succinimides. This chain process was initiated by a catalytic amount of fluoride salt, whereas reaction failed with the corresponding lithium enolate.     

MICROWAVE-ASSISTED N-ALKYLATION OF POTASSIUM PHTHALIMIDE AND POTASSIUM SUCCINIMIDE ONTO SILICA GEL IN DRY MEDIA

Synthesis of N-alkyl phthalimides and N-alkyl succinimides through alkylation of potassium phthalimide and potassium succinimide in dry media catalyzed by phase-transfer catalyst under microwave irradiation will be reported. The reactions were with fairly high yield.     

A novel asymmetric route to succinimides and derived compounds: synthesis of the lignan lactone (+)-hinokinin

A novel approach to chiral succinimides and derived compounds has been developed that involves chiral lithium amide desymmetrisation of an N-ortho-tert-butylphenyl succinimide to generate a putative atropisomeric intermediate enolate, alkylation of which enables access to the lignan lactone (+)-hinokinin.