3187-77-7Relevant academic research and scientific papers
Fe2Mn(μ3-O)(COO)6 Cluster Based Stable MOF for Oxidative Coupling of Amines via Heterometallic Synergy
Wang, Ying-Xia,Wang, Hui-Min,Meng, Pan,Song, Dong-Xia,Qi, Zhikai,Zhang, Xian-Ming
supporting information, p. 2983 - 2989 (2021/08/30)
The direct catalytic oxidative coupling of amines is one of the attracting methods for the synthesis of a variety of pharmaceutical or industrial needed imines. Numerous earth-abundant manganese based salts, oxides, and complexes have been applied in this reaction. However, these compounds suffered from difficult separation, large catalyst loading, complicated reactivation or indeterminate activity. Considering the facts that metal-organic frameworks (MOFs) with crystalline structure, precise composition, and enormous surface area have superior performance in heterogeneous catalytic reactions, herein, we introduced Mn into [Fe3(μ3-O)(CH3COO)6], one of the precursors for the preparation of stable MOFs, and got [Fe2Mn(μ3-O)(CH3COO)6] cluster. After ligand replacement with biphenyl-3,4’,5-tricarboxylic acid (BPTC), heterometallic cluster-based [Fe2Mn(μ3-O)(BPTC)2(DMF)2(H2O)] (1) was obtained. As expected, 1 is stable and able to catalyze the homo- or cross-coupling of amines effectively and selectively with 0.9 mol% catalyst loading at room temperature. Control experiments indicated that the catalytic activity of 1 mainly stems from Mn sites and that Fe synergistically contributes to the stability. Additionally, 1 is recyclable and can be reused easily for at least 8 runs without obvious decrease in catalytic ability. To our knowledge, 1 should be the first heterometallic cluster-based MOF with defined structure suitable for the synthesis of diverse imines from oxidative coupling of amines under mild conditions, which may shed light on the easy preparation of effective heterogeneous catalysts for organic synthesis.
Biocatalytic N-Alkylation of Amines Using Either Primary Alcohols or Carboxylic Acids via Reductive Aminase Cascades
Ramsden, Jeremy I.,Heath, Rachel S.,Derrington, Sasha R.,Montgomery, Sarah L.,Mangas-Sanchez, Juan,Mulholland, Keith R.,Turner, Nicholas J.
, p. 1201 - 1206 (2019/01/21)
The alkylation of amines with either alcohols or carboxylic acids represents a mild and safe alternative to the use of genotoxic alkyl halides and sulfonate esters. Here we report two complementary one-pot systems in which the reductive aminase (RedAm) from Aspergillus oryzae is combined with either (i) a 1° alcohol/alcohol oxidase (AO) or (ii) carboxylic acid/carboxylic acid reductase (CAR) to affect N-alkylation reactions. The application of both approaches has been exemplified with respect to substrate scope and also preparative scale synthesis. These new biocatalytic methods address issues facing alternative traditional synthetic protocols such as harsh conditions, overalkylation and complicated workup procedures.
Visible light photocatalytic aerobic oxidative synthesis of imines from alcohols and amines on dye-sensitized TiO2
Xu, Hui,Shi, Ji-Long,Hao, Huimin,Li, Xia,Lang, Xianjun
, p. 128 - 135 (2019/01/04)
A general visible light photocatalytic protocol for the synthesis of imines via a two-step one-pot route on alizarin red S (ARS)-sensitized TiO2 was uncovered. This efficient synthesis protocol involves one step of the highly selective formation of aldehydes from the oxidation of alcohols with O2 on ARS-sensitized TiO2 photocatalyst, and a subsequent step of condensation of newly formed aldehydes with various amines on TiO2 to afford imines in one pot. Anatase TiO2 provides a versatile platform for catalytic amounts of ARS (0.67 mol%) to facilitate the electron transfer from dye traversing its conduction band to O2 under green LED irradiation. Moreover, the Lewis acid sites of TiO2 can promote the formation of imines from aldehydes and amines in very high isolated yields. We took advantage of both the photocatalytic and catalytic properties of TiO2 to significantly expand the scope of imines. Our work suggests that the synthetic applications of TiO2 photocatalysis can be achievable under mild conditions by exploring the excellent functionalities of TiO2.
A General Way to Construct Arene-Fused Seven-Membered Nitrogen Heterocycles
Bakulina, Olga,Chizhova, Maria,Dar'in, Dmitry,Krasavin, Mikhail
, p. 362 - 371 (2018/01/27)
Imines react with seven-membered cyclic anhydrides (prepared from the corresponding dicarboxylic acids by a recently discovered in-situ cyclodehydration protocol) by the Castagnoli–Cushman reaction pathway to give privileged seven-membered arene-fused nitrogen-heterocyclic compounds with reagent-controlled diversity of the skeleton and peripheral groups.
Novel transition bimetal-organic frameworks: Recyclable catalyst for the oxidative coupling of primary amines to imines at mild conditions
Ge, Danhua,Qu, Genlong,Li, Xinming,Geng, Kaiming,Cao, Xueqin,Gu, Hongwei
, p. 5531 - 5536 (2016/07/06)
A novel type of transition bimetal-organic frameworks was described as a heterogeneous catalyst for the oxidative coupling of amines to imines under mild conditions, which was easily synthesized by the coordination assembly of manganese(ii) and cobalt(ii) with 1,3,5-benzenetricarboxylic acid (H3BTC) for the first time. The metal-organic framework material was characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, thermogravimetry and N2 sorption. As an environmentally benign heterogeneous catalyst, the catalytic ability of the metal-organic framework material was then detected to be excellent for the tert-butyl hydroperoxide (TBHP) promoted direct oxidative coupling of benzylamines to imines in excellent yields (up to 100%) in methanol for 3 h. More importantly, it could be recycled up to six runs, while still maintaining its high catalytic activity.
Reversible C-C bond activation enables stereocontrol in Rh-catalyzed carbonylative cycloadditions of aminocyclopropanes
Shaw, Megan H.,McCreanor, Niall G.,Whittingham, William G.,Bower, John F.
, p. 463 - 468 (2015/01/30)
Upon exposure to neutral or cationic Rh(I)-catalyst systems, amino-substituted cyclopropanes undergo carbonylative cycloaddition with tethered alkenes to provide stereochemically complex N-heterocyclic scaffolds. These processes rely upon the generation and trapping of rhodacyclopentanone intermediates, which arise by regioselective, Cbz-directed insertion of Rh and CO into one of the two proximal aminocyclopropane C-C bonds. For cyclizations using cationic Rh(I)-systems, synthetic and mechanistic studies indicate that rhodacyclopentanone formation is reversible and that the alkene insertion step determines product diastereoselectivity. This regime facilitates high levels of stereocontrol with respect to substituents on the alkene tether. The option of generating rhodacyclopentanones dynamically provides a new facet to a growing area of catalysis and may find use as a (stereo)control strategy in other processes.
Effect of N-Bound Organic Moiety in Dithiocarbamate (R2NCS-2) and trans Influence of Triphenylphosphine on NiS2PN Chromophore
Sathiyaraj, Ethiraj,Valarmathi, Panneerselvam,Thirumaran, Subbiah,Ciattini, Samuele,Gupta, Vivek K.,Kant, Rajni
, p. 1127 - 1137 (2015/08/04)
Three square planar Ni(II) complexes of the composition [Ni(bzcprdtc)2](1), [Ni(bzcprdtc)(NCS)(PPh3)](2) and [Ni(bzcprdtc)(PPh3)2]ClO4 (3)[(where bzcprdtc = N-benzyl-N-cyclopropyl-dithiocarbamate)] ha
Directing group enhanced carbonylative ring expansions of amino-substituted cyclopropanes: Rhodium-catalyzed multicomponent synthesis of N-heterobicyclic enones
Shaw, Megan H.,Melikhova, Ekaterina Y.,Kloer, Daniel P.,Whittingham, William G.,Bower, John F.
supporting information, p. 4992 - 4995 (2013/05/22)
Aminocyclopropanes equipped with suitable N-directing groups undergo efficient and regioselective Rh-catalyzed carbonylative C-C bond activation. Trapping of the resultant metallacycles with tethered alkynes provides an atom-economic entry to diverse N-heterobicyclic enones. These studies provide a blueprint for myriad N-heterocyclic methodologies.
Substituted 4-Oxo-1,2,3,4-tetrahydroquinoline-3-carboxylic esters by a tandem imine addition-SNAr reaction
Bunce, Richard A.,Schammerhorn, James E.,Sigle, Jessica
, p. 373 - 380 (2013/06/04)
A tandem imine addition-SNAr annulation reaction has been developed as a new approach to the synthesis of 4-oxo-1,2,3,4- tetrahydroquinoline-3-carboxylic esters. A series of these structures has been generated by reacting selected imines with tert-butyl 2-fluoro-5- nitrobenzoylacetate. Structural variations in the final products are accomplished by changing the substituents on the imine and the alkyl group of the ester. The title compounds are isolated as their enols in 55-97% yield without the need for added base or catalysts. The synthesis of the starting materials as well as mechanistic studies and further synthetic conversions of the products are presented.
Synthesis of iminonitriles by oxone/tbab-mediated one-pot oxidative three-component strecker reaction
Gualtierotti, Jean-Baptiste,Schumacher, Xavier,Wang, Qian,Zhu, Jieping
, p. 1380 - 1386 (2013/07/05)
Oxidative three-component reaction of aldehydes, amines, and TMSCN in a biphasic solvent system (toluene/H2O) containing Oxone, tetra-n-butylammonium bromide (TBAB) and sodium bicarbonate afforded α-iminonitriles in good to excellent yields. This oxidative Strecker reaction was applicable to a wide range of aldehydes and amines, aromatic or aliphatic, of different electronic and steric properties. Substituted 1-aza-2-cyano-1,3-dienes were also accessible using α,β-unsaturated aldehydes as inputs.
