- A Novel Synthetic Metal Catalytic System for Dehydrogenative Oxidation based on Redox of Polyaniline
-
Polyaniline serves as a synthetic metal catalyst with reversible redox under oxygen to induce dehydrogenative and/or decarboxylative oxidation of benzylamines and 2-phenylglycine into the corresponding imines and, in combination with copper(II) chloride or iron(III) chloride, dehydrogenation of cinnamyl alcohol into cinnamaldehyde possibly due to complexation.
- Hirao, Toshikazu,Higuchi, Masayoshi,Ikeda, Isao,Ohshiro, Yoshiki
-
-
Read Online
- Arene ci£h amination at nickel in terphenyl-diphosphine complexes with labile metal-arene interactions
-
The meta-terphenyl diphosphine, m-P2, 1, was utilized to support Ni centers in the oxidation states 0, I, and II. A series of complexes bearing different substituents or ligands at Ni was prepared to investigate the dependence of metal-arene interactions on oxidation state and substitution at the metal center. Complex (m-P2)Ni (2) shows strong Ni 0-arene interactions involving the central arene ring of the terphenyl ligand both in solution and the solid state. These interactions are significantly less pronounced in Ni0 complexes bearing L-type ligands (2-L: L=CH3CN, CO, Ph2CN2), NiIX complexes (3-X: X=Cl, BF4, N3, N3B(C 6F5)3), and [(m-P2)Ni IICl2] (4). Complex 2 reacts with substrates, such as diphenyldiazoalkane, sulfur ylides (Ph2Si£CH2), organoazides (RN3: R=para-C6H4OMe, para-C 6H4CF3, 1-adamantyl), and N2O with the locus of observed reactivity dependent on the nature of the substrate. These reactions led to isolation of an η1-diphenyldiazoalkane adduct (2-Ph2CN2), methylidene insertion into a Nii£P bond followed by rearrangement of a nickel-bound phosphorus ylide (5) to a benzylphosphine (6), Staudinger oxidation of the phosphine arms, and metal-mediated nitrene insertion into an arene Ci£H bond of 1, all derived from the same compound (2). Hydrogen-atom abstraction from a NiI-amide (9) and the resulting nitrene transfer supports the viability of Ni-imide intermediates in the reaction of 1 with 1-azido-arenes. Put a ring on it: The utilization of a meta-terphenyl diphosphine ligand leads to labile metal-arene interactions in Ni complexes in various oxidation states and coordination environments. When these complexes are treated with group-transfer reagents, such as diazoalkanes, sulfur ylides, or azides, various types of ligand-centered reactivity were observed, including methylidene insertion into a Pi£C bond and amination of an arene Ci£H bond. Copyright
- Herbert, David E.,Lara, Nadia C.,Agapie, Theodor
-
-
Read Online
- Synthesis of an elusive, stable 2-azaallyl radical guided by electrochemical and reactivity studies of 2-azaallyl anions
-
The super electron donor (SED) ability of 2-azaallyl anions has recently been discovered and applied to diverse reactivity, including transition metal-free cross-coupling and dehydrogenative cross-coupling processes. Surprisingly, the redox properties of
- Panetti, Grace B.,Carroll, Patrick J.,Gau, Michael R.,Manor, Brian C.,Schelter, Eric J.,Walsh, Patrick J.
-
p. 4405 - 4410
(2021/04/07)
-
- Scope and limitations of reductive amination catalyzed by half-sandwich iridium complexes under mild reaction conditions
-
The conversion of aldehydes and ketones to 1° amines could be promoted by half-sandwich iridium complexes using ammonium formate as both the nitrogen and hydride source. To optimize this method for green chemical synthesis, we tested various carbonyl substrates in common polar solvents at physiological temperature (37 °C) and ambient pressure. We found that in methanol, excellent selectivity for the amine over alcohol/amide products could be achieved for a broad assortment of carbonyl-containing compounds. In aqueous media, selective reduction of carbonyls to 1° amines was achieved in the absence of acids. Unfortunately, at Ir catalyst concentrations of 1 mM in water, reductive amination efficiency dropped significantly, which suggest that this catalytic methodology might be not suitable for aqueous applications where very low catalyst concentration is required (e.g., inside living cells).
- Nguyen, Dat P.,Sladek, Rudolph N.,Do, Loi H.
-
supporting information
(2020/07/15)
-
- Uniform Cu/chitosan beads as a green and reusable catalyst for facile synthesis of iminesviaoxidative coupling reaction
-
A nonprecious metal and biopolymer-based catalyst, Cu/chitosan beads, has been successfully prepared by using a software-controlled flow system. Uniform, spherical Cu/chitosan beads can be obtained with diameters in millimeter-scale and narrow size distribution (0.78 ± 0.04 mm). The size and morphology of the Cu/chitosan beads are reproducible due to high precision of the flow rate. In addition, the application of the Cu/chitosan beads as a green and reusable catalyst has been demonstrated using a convenient and efficient protocol for the direct synthesis of iminesviathe oxidative self- and cross-coupling of amines (24 examples) with moderate to excellent yields. Importantly, the beads are stable and could be reused more than ten times without loss of the catalytic performance. Furthermore, because of the bead morphology, the Cu/chitosan catalyst has greatly simplified recycling and workup procedures.
- Bunchuay, Thanthapatra,Chantiwas, Rattikan,Chutimasakul, Threeraphat,Intanin, Apichai,Na Nakhonpanom, Pakamon,Tantirungrotechai, Jonggol,Tirdtrakool, Warinda
-
p. 21009 - 21018
(2020/06/22)
-
- Reactions between 5-Nitroso-1,3-diphenyltetrazolium salts and electron-rich arenes, amines, thiophenol, sulfoxides, and thioanisole
-
A series of reactions between 5-nitroso-1,3-diphenyltetrazo-lium tetrafluoroborate and methoxybenzenes, amines, thiols, sulfoxides, and sulfides, most of which are generally accepted as being inert to nitroso groups, is reported here. The tetrazolium-activated nitroso functionality is capable of oxidizing the aforementioned substrates to give the corresponding oxidized products, and the nitroso tetrazolium itself is transformed into the corresponding amide or hydroxyamide, depending on the nature of the reaction partners. In the case of thioanisole, an addition product was obtained.
- Matsukawa, Yuta,Hirashita, Tsunehisa,Araki, Shuki
-
supporting information
p. 540 - 544
(2019/04/05)
-
- Suspending Ion Electrocatalysts in Charged Metal–Organic Frameworks to Improve the Conductivity and Selectivity in Electroorganic Synthesis
-
Electroorganic synthesis is an environmentally friendly alternative to traditional synthetic methods; however, the application of this strategy is heavily hindered by low product selectivity. Metal–organic frameworks (MOFs) exhibit high selectivity in numerous catalytic reactions; however, poor conductivity heavily limits the application of MOFs in electroorganic synthesis. To realize the electrocatalytic application of MOFs in selective electroorganic synthesis, a practically applicable strategy by suspending ion electrocatalysts in charged MOFs is herein reported. This approach could markedly improve the product selectivity in electroorganic synthesis. In the electrocatalytic oxidative self-coupling of benzylamine experiments, the imine product selectivity is markedly improved from 61.3 to 94.9 %, when the MOF-based electrocatalyst is used instead of the corresponding homogeneous electrocatalyst under the identical conditions. Therefore, this work opens a new route to improve the product selectivity in electroorganic synthesis.
- Guo, Wei-Wei,Zhang, Chi,Ye, Ji-Jie,Liu, Zi-Kun,Chen, Kai,Wu, Chuan-De
-
p. 3627 - 3634
(2019/07/31)
-
- Promoting Frustrated Lewis Pairs for Heterogeneous Chemoselective Hydrogenation via the Tailored Pore Environment within Metal–Organic Frameworks
-
Frustrated Lewis pairs (FLPs) have recently been advanced as efficient metal-free catalysts for catalytic hydrogenation, but their performance in chemoselective hydrogenation, particularly in heterogeneous systems, has not yet been achieved. Herein, we demonstrate that, via tailoring the pore environment within metal–organic frameworks (MOFs), FLPs not only can be stabilized but also can develop interesting performance in the chemoselective hydrogenation of α,β-unsaturated organic compounds, which cannot be achieved with FLPs in a homogeneous system. Using hydrogen gas under moderate pressure, the FLP anchored within a MOF that features open metal sites and hydroxy groups on the pore walls can serve as a highly efficient heterogeneous catalyst to selectively reduce the imine bond in α,β-unsaturated imine substrates to afford unsaturated amine compounds.
- Niu, Zheng,Zhang, Weijie,Lan, Pui Ching,Aguila, Briana,Ma, Shengqian
-
supporting information
p. 7420 - 7424
(2019/04/27)
-
- 2-Azaallyl Anions as Light-Tunable Super-Electron-Donors: Coupling with Aryl Fluorides, Chlorides, and Bromides
-
Herein, we present 2-azaallyl anions as colored super-electron-donors capable of reducing a collection of aryl halides via a single electron transfer and coupling with the corresponding radicals to forge new C?C bonds. This offers a robust approach for th
- Wang, Qianmei,Poznik, Michal,Li, Minyan,Walsh, Patrick J.,Chruma, Jason J.
-
p. 2854 - 2868
(2018/08/17)
-
- Biomimetic Oxidative Deamination Catalysis via ortho-Naphthoquinone-Catalyzed Aerobic Oxidation Strategy
-
An ortho-naphthoquinone-catalyzed oxidative deamination reaction has been developed where the molecular oxygen and water serve as the sole oxidant and nucleophile. The current aerobic deamination reaction proceeds via the ketimine formation between ortho-naphthoquinones and amines followed by the prototropic rearrangement and hydrolysis by water, representing a biomimetic oxidative deamination of amine species in the human body by the liver and kidneys. The compatibility of ortho-naphthoquinone organocatalysts with molecular oxygen and water opens up a new biomimetic catalyst system that can function as versatile deaminases for a variety of amine-containing molecules such as amino acids and DNA nuclear bases.
- Golime, Gangadhararao,Bogonda, Ganganna,Kim, Hun Young,Oh, Kyungsoo
-
p. 4986 - 4990
(2018/05/14)
-
- Metal-Organic Framework Anchored with a Lewis Pair as a New Paradigm for Catalysis
-
Lewis pair (LP) chemistry has shown broad applications in the catalysis field. However, one significant challenge has been recognized as the instability for most homogeneous LP catalysts upon recycling, thus inevitably leading to dramatic loss in catalytic activity. Additionally, current heterogeneous LP catalysts suffer from low surface area, which largely limits their catalytic efficiency, thereby restricting their potential applications. In this work, we report the successful introduction of LPs, classical and frustrated, into a metal-organic framework (MOF) that features high surface and ordered pore structure via a stepwise anchoring strategy. Not only can the LP be stabilized by the strong coordination interaction between the LP and MOF, but the resultant MOF-LP also demonstrates excellent catalysis performance with interesting size and steric selectivity. Given the broad applicability of LPs, our work therefore paves a way for advancing MOF-LP as a new paradigm for catalysis. Lewis pairs (LPs), classical and frustrated, are excellent prospects in catalysis, organic syntheses, biology, and material sciences. However, the instability of most LP catalysts leads to a dramatic loss in activities, thereby largely restricting their industrial applications. As robust porous materials, metal-organic frameworks (MOFs) offer a platform to stabilize homogeneous catalysts. Here, we show a strategy that grafts the LP catalyst on the MOF to minimize loss of LPs during catalysis and recycling. Our work reveals the enormous potential of MOFs as an appealing paradigm for the construction of efficient heterogeneous catalysts with interesting steric and size selectivity worthy of exploration. In addition, the strategies for anchoring a LP into a MOF as contributed herein can be readily applied for the task-specific design of functional catalysis materials for various applications. Lewis pairs (LPs), classical and frustrated, have been successfully introduced into and stabilized in a metal-organic framework (MOF). Benefiting from the robust framework and tunable porous structure of MOFs, the resultant MOF-LP demonstrates not only great recyclability but also excellent performance in the catalytic reduction of imines and hydrogenation of alkenes. The combination of LP and MOF therefore lays a foundation for developing a MOF-LP as a new paradigm for catalysis, particularly heterogeneous catalysis.
- Niu, Zheng,Bhagya Gunatilleke, Wilarachchige D.C.,Sun, Qi,Lan, Pui Ching,Perman, Jason,Ma, Jian-Gong,Cheng, Yuchuan,Aguila, Briana,Ma, Shengqian
-
supporting information
p. 2587 - 2599
(2018/12/02)
-
- Transition-Metal-Free Radical C(sp3)-C(sp2) and C(sp3)-C(sp3) Coupling Enabled by 2-Azaallyls as Super-Electron-Donors and Coupling-Partners
-
The past decade has witnessed the rapid development of radical generation strategies and their applications in C-C bond-forming reactions. Most of these processes require initiators, transition metal catalysts, or organometallic reagents. Herein, we report the discovery of a simple organic system (2-azaallyl anions) that enables radical coupling reactions under transition-metal-free conditions. Deprotonation of N-benzyl ketimines generates semistabilized 2-azaallyl anions that behave as super-electron-donors (SEDs) and reduce aryl iodides and alkyl halides to aryl and alkyl radicals. The SET process converts the 2-azaallyl anions into persistent 2-azaallyl radicals, which capture the aryl and alkyl radicals to form C-C bonds. The radical coupling of aryl and alkyl radicals with 2-azaallyl radicals makes possible the synthesis of functionalized amine derivatives without the use of exogenous radical initiators or transition metal catalysts. Radical clock studies and 2-azaallyl anion coupling studies provide mechanistic insight for this unique reactivity.
- Li, Minyan,Berritt, Simon,Matuszewski, Lucas,Deng, Guogang,Pascual-Escudero, Ana,Panetti, Grace B.,Poznik, Michal,Yang, Xiaodong,Chruma, Jason J.,Walsh, Patrick J.
-
supporting information
p. 16327 - 16333
(2017/11/22)
-
- Metal-free aerobic oxidative coupling of amines in dimethyl sulfoxide via a radical pathway
-
Metal-free oxidative coupling of amines is achieved simply by heating their dimethyl sulfoxide (DMSO) solution under oxygen as oxidant without any other catalysts or additives, accompanied by the formation of an equimolar amount of dimethyl sulfone (DMSO2). EPR experiments indicate that the reaction proceeds via a radical pathway. DMSO may play a triple role as solvent, radical initiator and co-reductant.
- Lin, Mu,Wang, Zikuan,Fang, Huayi,Liu, Lianghui,Yin, Haolin,Yan, Chun-Hua,Fu, Xuefeng
-
p. 10861 - 10864
(2016/02/05)
-
- Bioinspired organocatalytic aerobic C-H oxidation of amines with an ortho -quinone catalyst
-
A simple bioinspired ortho-quinone catalyst for the aerobic oxidative dehydrogenation of amines to imines is reported. Without any metal cocatalysts, the identified optimal ortho-quinone catalyst enables the oxidations of α-branched primary amines and cyclic secondary amines. Mechanistic studies have disclosed the origins of different performances of ortho-quinone vs para-quinone in biomimetic amine oxidations.
- Qin, Yan,Zhang, Long,Lv, Jian,Luo, Sanzhong,Cheng, Jin-Pei
-
supporting information
p. 1469 - 1472
(2015/03/30)
-
- Palladium-catalyzed regioselective arylation of 1,1,3-triaryl-2-azaallyl anions with aryl chlorides
-
A regioselective arylation of 1,1,3-triaryl-2-azaallyl anions with aryl chlorides is described. The palladium-NIXANTPHOS-based catalyst affords diarylmethylamine derivatives in good yield and without product isomerization. A gram scale sequential one-pot ketimine synthesis/arylation protocol was also developed.
- Li, Minyan,Berritt, Simon,Walsh, Patrick J.
-
supporting information
p. 4312 - 4315
(2014/10/15)
-
- Synthesis of diarylmethylamines via palladium-catalyzed regioselective arylation of 1,1,3-triaryl-2-azaallyl anions
-
Diarylmethylamines are of great interest due to their prevalence in pharmaceutical chemistry. As a result, new methods for their synthesis are in demand. Herein, we report a versatile protocol for the synthesis of diarylmethylamine derivatives involving palladium-catalyzed arylation of in situ generated 2-azaallyl anion intermediates. The 2-azaallyl anions are generated by reversible deprotonation of readily available aldimine and ketimine precursors. Importantly, the arylated aldimine and ketimine products do not undergo isomerization under the reaction conditions. Scale-up of the arylation and hydrolysis of the resulting products to furnish diarylmethylamines were also successfully performed. This journal is the Partner Organisations 2014.
- Li, Minyan,Yuecel, Baris,Adrio, Javier,Bellomo, Ana,Walsh, Patrick J.
-
p. 2383 - 2391
(2014/05/20)
-
- Ionic-liquid-assisted metal-free oxidative coupling of amines to give imines
-
An oxidative coupling of amines to give imines in ionic liquids (ILs) under metal-free aerobic conditions has been developed. The high efficiency achievable in ILs is mechanistically explained in terms of activation of the starting materials (benzylamine and molecular oxygen) by an initial electron transfer, promoted by the ionic nature of the solvent. Reactivity data of variously p-substituted benzylamines show a general deactivating effect, which would imply a change in the rate-determining step in the reaction mechanism.
- Monopoli, Antonio,Cotugno, Pietro,Iannone, Francesco,Ciminale, Francesco,Dell'Anna, Maria Michela,Mastrorilli, Piero,Nacci, Angelo
-
supporting information
p. 5925 - 5931
(2015/03/30)
-
- Azobisisobutyronitrile initiated aerobic oxidative transformation of amines: Coupling of primary amines and cyanation of tertiary amines
-
In the presence of a catalytic amount of radical initiator AIBN, primary amines are oxidatively coupled to imines and tertiary amines are cyanated to α-aminonitriles. These "metal-free" aerobic oxidative coupling reactions may find applications in a wide
- Liu, Lianghui,Wang, Zikuan,Fu, Xuefeng,Yan, Chun-Hua
-
supporting information
p. 5692 - 5695
(2013/01/15)
-
- Taking the F out of FLP: Simple lewis acid-base pairs for mild reductions with neutral boranes via borenium ion catalysis
-
Discrete three-coordinate borenium salts 1c and 1d are accessed by cooperative Lewis acid-base pair-mediated heterolytic splitting of the B-H bond in pinacolborane by B(C6F5)3DABCO and Ph 3C+/DABCO, respectively. The resulting salts are competent catalysts in the reduction of a broad range of imines and can be generated in situ. Moreover, a mechanistic framework for borenium catalysis based on experimental evidence is proposed. The reaction is suggested to proceed by borenium activation of the imine substrate followed by counterintuitive hydride delivery from HBPin (with the assistance of DABCO) rather than from the HB(C6F5)3- anion, contrary to typical mechanisms of reduction in FLP systems.
- Eisenberger, Patrick,Bailey, Adrian M.,Crudden, Cathleen M.
-
supporting information
p. 17384 - 17387
(2013/01/15)
-
- Metal-free aerobic oxidative coupling of amines to imines
-
Oxidative coupling of primary amines to imines is achieved with high to moderate yields by refluxing suspensions of amines and water under one atmosphere dioxygen without any additives. Tandem acid-free aza Diels-Alder reactions for synthesis of N-alkyl-4-pyridones are also accomplished. The Royal Society of Chemistry 2011.
- Liu, Lianghui,Zhang, Siyu,Fu, Xuefeng,Yan, Chun-Hua
-
supporting information; experimental part
p. 10148 - 10150
(2011/11/04)
-
- Highly active and selective gold catalysts for the aerobic oxidative condensation of benzylamines to imines and one-pot, two-step synthesis of secondary benzylamines
-
Supported gold nanoparticles catalyze the oxidation of benzylamines to N-benzylidene benzylamines by molecular oxygen in toluene. The process is general, and para-substituted benzylamines as well as heterocyclic methanamines undergo oxidative condensation. 1-Phenylethanamine and diphenylmethanamine form imines with much less selectivity than benzylamines due to the unfavourable steric hindrance introduced by the substituents at the α-carbon. Secondary and tertiary dibenzyl and tribenzylamines form N-benzylidene benzylamines accompanied with aromatic ketones and oximes arising from C-N bond rupture. The efficiency of gold catalyst increases exponentially as the average particle size is reduced, and the TOF increases when the gold crystallite size is decreased. The solid support plays an important role as it has been found that gold supported on active carbon is more efficient than gold supported on anatase. Although palladium nanoparticles are also active in promoting benzylamine oxidation, only the catalyst based on platinum was found to exhibit an activity comparable to that of gold. Cross condensation of benzylamines in the presence of aromatic or aliphatic primary amines forms the mixed N-aryl or N-alkyl benzylimines with high yields. A one-pot, two-step procedure using a single gold catalyst has been devised to produce secondary symmetric and asymmetric amines derived from benzylamines with high atom efficiency.
- Grirrane, Abdessamad,Corma, Avelino,Garcia, Hermenegildo
-
experimental part
p. 138 - 144
(2009/09/07)
-
- Further insight into the reaction of electrogenerated 0-quinone with amino-alcohols and amines. Products and mechanism
-
Using 2,3,4-trihydroxybenzophenone as the starting material, the reaction of the electrogenerated 3,4-quinone with amino-alcohols and amines HC(R1,R2)-NH2 is suggested to proceed via an ionic mechanism that would involve a C(3) aminated carbinolamine intermediate and would afford, after dehydration, a 3,4-iminoquinone species. The subsequent step would consist either of a transamination reaction, or of the formation of a spiro aminoketal species (when using amino-alcohols as the substrate), or of a redox cycling reaction allowing the isolation of 3,4-alkylaminophenol derivatives.
- Largeron, Martine,Neudorffer, Anne,Fleury, Maurice-Bernard
-
p. 2721 - 2727
(2007/10/03)
-
- Dimerization of Anilines and Benzylamines with Mercury(II) Oxide-Iodine Reagent
-
By treatment with mercury(II) oxide-iodine reagent in dichloromethane at room temperature, substituted anilines were transformed to the corresponding azobenzenes. A similar treatment of benzylamines and benzhydrylamine gave N-benzylidenebenzylamines and N-benzhydrylidene-benzhydrylamine, respectively. α-Alkyl-substituted benzylamines gave diazenes and the corresponding phenyl ketones, competitively. An azine was obtained by interaction with the reagent of a benzylamine carrying an electron-withdrawing substituent at the α position, such as ethyl phenylglycinate.
- Orito, Kazuhiko,Hatakeyama, Takahiro,Takeo, Mitsuhiro,Uchiito, Shiho,Tokuda, Masao,Suginome, Hiroshi
-
p. 8403 - 8410
(2007/10/03)
-
- Stable nitroxyl radicals with a hydrogen atom at α-carbon atom of nitroxyl group
-
Nitroxyl radicals containing the diphenylmethyl group as one of the substituents at the nitroxyl group are stable compounds that can be isolated in an individual state. N-(2-Hydroxy-3-methyl-2-phenylcyclohexyl)-N-diphenylmethylnitroxyl was characterized b
- Reznikov,Gutorov,Gatilov,Rybalova,Volodarsky
-
p. 384 - 392
(2007/10/03)
-
- AN EXPLORATIVE INVESTIGATION INTO THE REACTION OF AMMONIA WITH KETONES. MEDIATED BY LOW-VALENT TITANIUM
-
Mediated by low-valent titanium, generated from TiCl3/LiAl4, ammonia is incorporated into benzophenone to give N-(diphenylmethylene)-N-(diphenylmethyl) amine in a synthetically useful reaction.A good yield (65 percent) requires that the temperatures of the reaction stages are well controled and that ammonia and ketone are simultaneously introduced keeping their molar ration 1:1.The possible sequence of reactions is discussed.
- Volckaerts, E.,Geise, H. J.,Daelmans, F.
-
p. 503 - 508
(2007/10/02)
-
- RADICAL CATION INTERMEDIATES IN THE FORMATION OF SCHIFF BASES ON IRRADIATED SEMICONDUCTOR POWDERS
-
Photocatalytic oxidation of several primary aliphatic amines on irradiated TiO2 powders suspended in anhydrous acetonitrile led to good yields of the corresponding symmetrical N-alkylidene amines.Mechanistic electrochemical investigation of the reaction revealed intermediate formation of an immonium cation in an ECE route.This species is generated via electrooxidation of an α-amino radical formed by deprotonation of the primary oxidation product, an aminium cation radical.The influence of the metal oxide surface on radical cation reactivity is discussed.
- Fox, Marye Anne,Younathan, Janet N.
-
p. 6285 - 6292
(2007/10/02)
-
- The Photochemical 1,5-Benzoyl Migration in 2,2-Diaryl-1,4,4-triphenyl-3-azabut-3-en-1-ones. A Novel Rearrangement in β,γ-Unsaturated Enone Systems
-
The synthesis of 2,2-diphenyl- and 2,2-bis(p-chlorophenyl)-1,4,4-triphenyl-3-azabut-3-en-1-one is described.The photochemical reactivity of these compounds is described and interpreted in terms of 1,5-benzoyl migration, the terminus of which rearrangement is a phenyl ring.This type of reactivity is novel for β,γ-unsaturated systems.
- Armesto, Diego,Gallego, Mar G.,Horspool, William M.,Perez-Ossorio, Rafael
-
p. 799 - 804
(2007/10/02)
-
- Aroylation of Carbanions Derived from N-(Diphenylmethyl)arylmethanimines. A Synthesis of 4-Aroyloxy-2-azabuta-1,3-dienes
-
The acylation of carbanions derived from N-(diphenylmethyl)arylmethanimines using aroyl chlorides, allows the preparation of a new type of substituted 2-azabuta-1,3-dienes in which the imino group is conjugated with an enol ester.The reaction is quite general and facilitates the preparation of a wide range of 2-azadienes with electron-donating and electron-withdrawing groups on the phenyl rings.The site selectivity for the attack of the electrophile on the aza-allyl anion can be controlled by the substituents on the carbanion and on the hardness of the electrophile.
- Armesto, Diego,Ortiz, Maria J.,Perez-Ossorio, Rafael
-
p. 2021 - 2026
(2007/10/02)
-
- Steric, Conformational, and Electronic Effects as Revealed by Acidities of Substituted Xanthenes and Reactions of Substituted Xanthenyl and Related Carbanions with Benzyl Chloride
-
Equilibrium acidities in Me2SO solution for 9-substituted xanthenes (9-G-XnH) with G = H, CN, PhS, PhSO2, CO2Me, and Ar are reported.Comparison of these acidities with those of related compounds, GCH2CN, 9-G-FlH (9-substituted fluorenes), and GCHPh2, show
- Bordwell, Frederick G.,Hughes, David L.
-
p. 2216 - 2222
(2007/10/02)
-
- Bis(acetylacetonato)copper(II) Catalysed Reaction of Diphenyldiazomethane with Primary Amines
-
The titel reaction using (+/-)-α-phenylethylamine, benzhydrylamine and (+/-)-α-p-tolylethylamine as primary amines leads to the formation of benzophenone N-substituted imines (IVa-c).The insertion of diphenylcarbene, formed from the decomposition of diphe
- Mehrotra, K. N.,Singh, G. S.
-
p. 672 - 673
(2007/10/02)
-
- Photochemical Transformations of 1,2-Diketones and Benzhydrylamine
-
Photolysis of a mixture of substituted 1,2-diketones and benzhydrylamine (in 1:2 mole ratio) in benzene gave N-benzhydrylidenebenzhydrylamine, N-(diarylmethyl)benzamides, acyloins (3), N-(arylmethylene)benzhydrylamines, and benzophenone separated by fractional crystallization and column chromatogaphy.The products have been characterised by analytical and spectral (IR, UV, and NMR) data and the structural assignments confirmed by the comparison (IR spectra and undepressed mixed mp) with authentic samples.Acyloins (3) are precursors for N-(diarylmethyl)benzamides and N-(arylmethylene)benzhydrylamines.A tentative mechanistic route for the formation of products has been suggested.
- Mehrotra, Kailash Nath,Pandey, Ganesh Prasad
-
p. 1081 - 1084
(2007/10/02)
-