60293-41-6Relevant academic research and scientific papers
Synthesis of β-Phosphinolactams from Phosphenes and Imines
Fu, Xingyang,Li, Xinyao,Xu, Jiaxi
supporting information, p. 8733 - 8737 (2021/11/17)
Various cis-β-phosphinolactams are synthesized stereoselectively for the first time from imines and diazo(aryl)methyl(diaryl)phosphine oxides under microwave irradiation. Diazo(aryl)methyl(diaryl)phosphine oxides first undergo the Wolf rearrangement to generate phosphenes. Imines nucleophilically attack the phosphenes followed by an intramolecular nucleophilic addition via less steric transition states to give final cis-β-phosphinolactams. C-Styrylimines generally give rise to β-phosphinolactams in higher yields than C-arylimines. The stereoselectivity and proposed mechanism are rationalized by DFT theoretical calculation.
Homoallylic amines as efficient chiral inducing frameworks in the conjugate addition of amides to α,β-unsaturated esters. An entry to enantio-enriched diversely substituted amines
Anani, Lilia,Behr, Jean-Bernard,Coelho, Aurélien,Machado-Rodrigues, Carine,Massicot, Fabien,Rogier, Johann,Vasse, Jean-Luc
supporting information, p. 2632 - 2636 (2020/04/17)
The diastereoselective conjugate addition of secondary homoallylamines, obtained in the enantioenriched form via allylmetallation of imines, to α,β-unsaturated esters is reported. This method allows access to valuable building blocks as well as heterocyclic skeletons, providing tertiary amines bearing two chains integrating a stereogenic center adjacent to the nitrogen atom.
Periselectivity in the aza-Diels–Alder reaction of 1-azadienes with α-oxoketenes: A combined experimental and theoretical study
Coquerel, Yoann,Dauvergne, Guillaume,Presset, Marc,Rajzmann, Michel,Rodriguez, Jean
, (2020/10/29)
Inversions in the periselectivity of formal aza-Diels–Alder cycloadditions between α-oxoketenes generated by a thermally-induced Wolff rearrangement and 1-azadienes were observed experimentally as a function of the α-oxoketene and the 1-azadiene, as well as the reaction temperature and time. Some unexpected inversion in the diastereoselectivity was observed, too. These variations in selectivities were fully rationalized by computational modeling using density functional theory (DFT) methods.
Efficient Co-Catalyzed Double Hydroboration of Nitriles: Application to One-Pot Conversion of Nitriles to Aldimines
Gudun, Kristina A.,Slamova, Ainur,Hayrapetyan, Davit,Khalimon, Andrey Y.
, p. 4963 - 4968 (2020/04/17)
The commercially available and bench-stable Co(acac)2/dpephos system is employed as a precatalyst for selective and efficient room temperature hydroboration of organic nitriles with HBPin to produce a series of N,N-diborylamines [RN(BPin)2], which react in situ with aldehydes to give aldimines. Formation of aldimines from N,N-diborylamines does not require a dehydrating agent, is applicable to a wide range of N,N-diborylamine and aldehyde substrates and is highly chemoselective, being unaffected by various common functional groups, such as alkenes, alkynes, secondary amines, ketones, esters, amides, carboxylic acids, pyridines, nitriles, and nitro compounds. The overall transformation represents a synthetically valuable approach to aldimines from nitriles and can be performed in a sequential one-pot manner, tolerating ester, lactone, carboxamide and unactivated alkene functionalities.
Development of Chiral Spiro Phosphoramidites for Rhodium-Catalyzed Enantioselective Reactions
Zheng, Zhiyao,Cao, Yuxi,Zhu, Dongsheng,Wang, Zheng,Ding, Kuiling
supporting information, p. 9491 - 9497 (2019/04/08)
A series of 1,1′-spirobiindane-7,7′-diol (SPINOL) analogues bearing a 2,2′-dimethyl-, cyclopentyl-, or cyclohexyl-fused ring were synthesized, and their distinct structural features were elucidated by X-ray crystallography. On the basis of these scaffolds, chiral monophosphoramidite ligands 6 a–m were synthesized, which demonstrated excellent enantioselectivity in RhI-catalyzed asymmetric hydrogenation of a dehydro amino acid methyl ester. Ligands 6 a–m were also successfully applied in the RhI-catalyzed enantioselective [4+2] cycloaddition of α,β-unsaturated imines with isocyanates, which afforded the corresponding pyrimidinones in good yields (60–92 %) with high enantioselectivities (75–92 % ee).
One-Pot Reductive Allylation of Amides by Using a Combination of Titanium Hydride and an Allylzinc Reagent: Application to a Total Synthesis of (-)-Castoramine
Itabashi, Suguru,Shimomura, Masashi,Sato, Manabu,Azuma, Hiroki,Okano, Kentaro,Sakata, Juri,Tokuyama, Hidetoshi
supporting information, p. 1786 - 1790 (2018/07/03)
A one-pot direct reductive allylation protocol has been developed for the synthesis of secondary amines by using titanium hydride and an allylzinc reagent. This protocol is applicable to a broad range of substrates, including acyclic amides, benzamides, α,β-unsaturated amides, and lactams. The stereochemical outcome obtained from the reaction with crotylzinc reagent suggested that the allylation reaction proceeds through a six-membered cyclic transition state. A total synthesis of (-)-castoramine was accomplished by following this protocol for the highly stereoselective construction of contiguous stereocenters.
A metallopeptoid as an efficient bioinspired cooperative catalyst for the aerobic oxidative synthesis of imines
Chandra Mohan, Darapanani,Sadhukha, Arghya,Maayan, Galia
, p. 139 - 144 (2017/10/16)
Enzymatic catalysis is largely based on intramolecular cooperativity between a metal center and functional organic molecules located on one scaffold. Inspired by this concept we have designed the metallopeptoid trimer BT, which is a unique intramolecular cooperative oxidation catalyst incorporating two catalytic centers, phenanthroline-copper and TEMPO, as well as one non-catalytic benzyl group. Herein we explore the capability of BT to act as an efficient catalyst for the oxidative synthesis of imines, which are versatile intermediates in the fine chemicals and pharmaceutical industries. We demonstrate that BT, combined with CuI, can catalyze the production of benzyl, aryl, heteroaryl, allylic and aliphatic imines from various alcohols and amines with a turn-over-number up to 45 times higher than this achieved when phenanthroline, copper and TEMPO are mixed in solution. Moreover, in low catalyst(s) loading, BT enables transformations that are not possible when a mixture of the individual catalysts is employed.
Aerobic oxidative coupling of alcohols and amines towards imine formation by a dicopper(I,I) catalyst
Dutta, Indranil,De, Subhabrata,Yadav, Sudhir,Mondol, Ranajit,Bera, Jitendra K.
, p. 117 - 124 (2017/09/30)
A dicopper(I,I) complex [Cu2(L1) (Cl)2] (1), bearing a Cu2Cl2 core spanned by a naphthyridine–diimine ligand is synthesized by the treatment of CuCl with 2,7–bis(N–mesitylmethylimino)–1,8–naphthyridine (L1). The catalytic efficacy of 1 is assessed for aerobic oxidative synthesis of imines from alcohols and amines. The title complex is found to be an excellent catalyst for a wide variety of alcohols and amines. Kinetic experiments revealed the involvement of both copper ions in the aerobic oxidation process. The general utility of naphthyridine based ligands to favour a possible bimetallic pathway for a catalytic reaction is demonstrated here.
Modular access to vicinally functionalized allylic (thio)morpholinonates and piperidinonates by substrate-controlled annulation of 1,3-azadienes with hexacyclic anhydrides
Braunstein, Hannah,Langevin, Spencer,Khim, Monique,Adamson, Jonathan,Hovenkotter, Katie,Kotlarz, Lindsey,Mansker, Brandon,Beng, Timothy K.
supporting information, p. 8864 - 8872 (2016/10/03)
A modular substrate-controlled hexannulation of inherently promiscuous 1,3-azadienes with hexacyclic anhydrides, which affords versatile vicinally functionalized allylic lactams, in high yields, regio- and stereoselectivities is described.
Cycloamidination of Aminoalkenes with Nitriles: Synthesis of Substituted 2-Imidazolines and Tetrahydropyrimidines
Huang, Shujian,Shao, Yinlin,Zhang, Lixin,Zhou, Xigeng
supporting information, p. 14452 - 14456 (2016/01/25)
The first catalytic cycloamidination of aminoalkenes with nitriles has been achieved by using rare-earth complexes. This reaction is equivalent to the desired intramolecular hydroamination of alkenylamidines, and allows a new direct access to substituted 2-imidazolines and tetrahydropyrimidines in high yields under operationally simple reaction conditions. Moreover, the methodology is also efficient for synthesis of symmetric and unsymmetric bridged diimidazolines. Compared with the traditional stepwise-mediated synthetic approaches, the present method avoids the use of additives and harsh reaction conditions, and thus leads to a completely different product distribution. Mechanistic data suggest that the reaction involves the initial NH activation by lanthanide complex followed by nitrile insertion into a Ln-N bond to form an amidinate lanthanide intermediate which undergoes the cyclization.
