- Synthesis of Diprotected Monosubstituted Hydrazine Derivatives from tert-Butyl Carbazates and Boronic Acids
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(Equation presented) Diprotected monosubstituted hydrazine derivatives have been prepared via the reaction of tert-butyl carbazates with boronic acids catalyzed by cuprous chloride at room temperature.
- Kabalka, George W.,Guchhait, Sankar K.
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- A Modular Approach to Arylazo-1,2,3-triazole Photoswitches
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Azoheteroarenes make up an emerging class of photoswitchable compounds with unique photophysical properties and advantages over traditional azobenzenes. Therefore, methods for synthesizing azoheteroarenes are highly desirable. Here, we utilize azide-alkyne click chemistry to access arylazo-1,2,3-triazoles, a previously unexplored class of azoheteroarenes that exhibit high thermal stabilities and near-quantitative bidirectional photoconversion. Controlling the catalyst or 1,3-dipole grants access to both regioisomeric arylazotriazoles and arylazoisoxazoles, highlighting the versatility of our approach.
- Olson, David E.,Tombari, Robert J.,Tuck, Jeremy R.,Yardeny, Noah
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- Copper salt catalyzed addition of arylboronic acids to azodicarboxylates
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The addition of arylboronic acids 1 to azodicarboxylates 2 in the presence of a catalytic amount of a copper salt under mild reaction conditions gives aryl-substituted hydrazines 3 in high yields. The reaction is tolerant of a wide variety of functional groups.
- Uemura, Takeshi,Chatani, Naoto
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Read Online
- Synthesis of 1,2-Dihydroquinolines via Hydrazine-Catalyzed Ring-Closing Carbonyl-Olefin Metathesis
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The synthesis of 1,2-dihydroquinolines by the hydrazine-catalyzed ring-closing carbonyl-olefin metathesis (RCCOM) of N-prenylated 2-aminobenzaldehydes is reported. Substrates with a variety of substitution patterns are shown. With an acid-labile protecting group on the nitrogen atom, in situ deprotection and autoxidation furnish quinoline. In comparison with related oxygen-containing substrates, the cycloaddition step of the catalytic cycle is shown to be slower, but the cycloreversion is found to be more facile.
- Zhang, Yunfei,Sim, Jae Hun,Macmillan, Samantha N.,Lambert, Tristan H.
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supporting information
p. 6026 - 6030
(2020/08/05)
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- Decarboxylative Amination: Diazirines as Single and Double Electrophilic Nitrogen Transfer Reagents
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The ubiquity of nitrogen-containing small molecules in medicine necessitates the continued search for improved methods for C-N bond formation. Electrophilic amination often requires a disparate toolkit of reagents whose selection depends on the specific structure and functionality of the substrate to be aminated. Further, many of these reagents are challenging to handle, engage in undesired side reactions, and function only within a narrow scope. Here we report the use of diazirines as practical reagents for the decarboxylative amination of simple and complex redox-active esters. The diaziridines thus produced are readily diversifiable to amines, hydrazines, and nitrogen-containing heterocycles in one step. The reaction has also been applied in fluorous phase synthesis with a perfluorinated diazirine.
- Chandrachud, Preeti P.,Wojtas, Lukasz,Lopchuk, Justin M.
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supporting information
p. 21743 - 21750
(2021/01/11)
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- Photocatalytic esterification under Mitsunobu reaction conditions mediated by flavin and visible light
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The usefulness of flavin-based aerial photooxidation in esterification under Mitsunobu reaction conditions was demonstrated, providing aerial dialkyl azodicarboxylate recycling/generation from the corresponding dialkyl hydrazine dicarboxylate. Simultaneously, activation of triphenylphosphine (Ph3P) by photoinduced electron transfer from flavin allows azo-reagent-free esterification. An optimized system with 3-methylriboflavin tetraacetate (10%), oxygen (terminal oxidant), visible light (450 nm), Ph3P, and dialkyl hydrazine dicarboxylate (10%) has been shown to provide efficient and stereoselective coupling of various alcohols and acids to esters with retention of configuration.
- M?rz,Chudoba,Kohout,Cibulka
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supporting information
p. 1970 - 1975
(2017/03/11)
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- A containing hydrazine nitrogen phosphorus ligand complex and its in ester the application of the catalytic hydrogenation of
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The invention relates to a composition containing hydrazine nitrogen and phosphorus ligands and application of the composition in catalytic hydrogenation with ester. The invention relates to the metal composition which is shown by a general formula MXY (L) and a method for preparing alcohols through hydrogenation reduction of carbonyl compounds such as ketones and estersby using the composition as catalysts. In the MXY (L), the M is metal Fe, Ru, Os, Co, Rh, Ir and other transition group metal, the X and the Y can be the same anion ligand or different anion ligands, and the L is a tetradentate ligand containing -NH-pyridyl and two heteroatoms. The composition disclosed by the invention has the advantages that the catalytic activity is high and the stability is strong.
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Paragraph 0088; 0089; 0090
(2017/01/31)
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- Visible light-mediated decarboxylative amination of indoline-2-carboxylic acids catalyzed by Rose Bengal
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A visible light-induced decarboxylative amination of indoline-2-carboxylic acids and azodicarboxylate esters has been developed, in which the oxidation of α-amino acids provides a versatile CO2-extrusion platform to generate α-aminoalkyl radicals. The corresponding products were obtained with yields of up to 72% catalyzed by a metal-free photocatalyst under mild conditions.
- Zhang, Meng-Jie,Schroeder, Griffin M.,He, Yan-Hong,Guan, Zhi
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p. 96693 - 96699
(2016/10/25)
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- ORGANOCATALYTIC CARBONYL-OLEFIN AND OLEFIN-OLEFIN METATHESIS
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The present invention provides, inter alia, organocatalytic carbonyl-olefin metathesis process. This process involves contacting a carbonyl-containing moiety with an olefin-containing moiety in the presence of a catalyst and under conditions sufficient to form a metathesis product with the proviso that the process takes place in the absence of photochemical promotion, stoichiometric amounts of transition metals, and Brnsted and Lewis acid catalysts. The present invention also provides an organocatalytic olefin-olefin metathesis process. This process involves contacting a first olefin-containing moiety with a second olefin-containing moiety in the presence of a catalyst and under conditions sufficient to form a metathesis product with the proviso that the process takes place in the absence of stoichiometric amounts of transition metals. Products made by the processes disclosed herein are also provided.
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Paragraph 0160
(2014/02/16)
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- Efficient synthesis of cyclopropylhydrazine salts
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An efficient procedure for the synthesis of cyclopropylhydrazine in the form of its salts is reported. The copper salt-catalyzed addition of cyclopropylboronic acid to the azo group of di-tert-butyl azodicarboxylate and subsequent deprotection gave the cy
- Shibue, Taku,Fukuda, Yasumichi
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p. 4102 - 4104
(2014/07/22)
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- Convenient synthesis of monobenzylated hydrazides via aqueous zinc-mediated addition reactions
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Addition of substituted benzyl bromides to dialkyl azodicarboxylates under aqueous zinc-mediated addition conditions occurs readily to afford monobenzylated hydrazides in good to excellent yields. The reaction is tolerant of a variety of substituents on the benzyl bromide ring. Several dialkyl azodicarboxylates were successfully tested under the reaction conditions. The limitations of the reaction are also addressed.
- Breton, Gary W.
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supporting information
p. 1128 - 1136
(2014/04/03)
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- Organocatalytic carbonyl-olefin metathesis
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The development of a catalytic carbonyl-olefin metathesis strategy is reported, in the context of the ring-opening metathesis of cyclopropenes with aldehydes using a simple hydrazine catalyst. The key to this reaction is a conceptual blueprint for metathesis chemistry that forgoes the traditional reliance on [2 + 2] cycloaddition modes in favor of a [3 + 2] paradigm.
- Griffith, Allison K.,Vanos, Christine M.,Lambert, Tristan H.
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supporting information
p. 18581 - 18584
(2013/01/15)
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- α-Aroyloxyaldehydes: Scope and limitations as alternatives to α-haloaldehydes for NHC-catalysed redox transformations
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α-Aroyloxyaldehydes are readily prepared bench stable synthetic intermediates. Their ability to act as α-haloaldehyde surrogates for NHC-promoted redox esterifications and in [4+2] cycloadditions is described.
- Ling, Kenneth B.,Smith, Andrew D.
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supporting information; experimental part
p. 373 - 375
(2011/02/24)
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- Development of cyclic hydrazine and hydrazide type organocatalyst-mechanistic aspects of cyclic hydrazine/hydrazide-catalyzed diels-alder reactions
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Some hydrazines and hydrazides were prepared and screened for their catalytic efficiencies in Diels-Alder reactions. 1H-NMR studies and ab initio calculations revealed that catalytic efficiencies of these catalysts are greatly dependent on the release of the catalysts from the Diels-Alder adducts.
- Suzuki, Ichiro,Hirata, Ai,Takeda, Kei
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scheme or table
p. 851 - 863
(2009/12/01)
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- Effective strategy for the systematic synthesis of hydrazine derivatives
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A new and efficient strategy for the systematic synthesis of hydrazine derivatives is reported. It allows the synthesis of up to tetrasubstituted hydrazine derivatives with minimal number of steps using only one protecting group or without any of them at all. Simple and readily available starting materials such as hydrazine hydrate or phenylhydrazine can be used. A variety of substrates were used to investigate scope and limitations of this strategy, additionally one full synthetic sequence was performed.
- Bredihhin, Aleksei,M?eorg, Uno
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p. 6788 - 6793
(2008/12/20)
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- Catalytic activation of N-N multiple bonds: A homogeneous palladium catalyst for mechanistically unprecedented reduction of azo compounds
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Just two oxidation states are involved in the homogeneous reduction of azo compounds at a single palladium catalyst site. The reaction proceeds through an intermediate state in which the catalyst displays a novel palladadiaziridine structure, and ethanol or related alcohols can be employed as the terminal reducing agent (see scheme). (Chemical Equation Presented).
- Muniz, Kilian,Nieger, Martin
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p. 2305 - 2308
(2007/10/03)
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- Hydrazines and azides via the metal-catalyzed hydrohydrazination and hydroazidation of olefins
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The discovery, study, and implementation of the Co- and Mn-catalyzed hydrohydrazination and hydroazidation reactions of olefins are reported. These reactions are equivalent to direct hydroaminations of C-C double bonds with protected hydrazines or hydrazoic acid but are based on a different concept in which the H and the N atoms come from two different reagents, a silane and an oxidizing nitrogen source (azodicarboxylate or sulfonyl azide). The hydrohydrazination reaction using di-tert-butyl azodicarboxylate is characterized by its ease of use, large functional group tolerance, and broad scope, including mono-, di-, tri-, and tetrasubstituted olefins. Key to the development of the hydroazidation reaction was the use of sulfonyl azides as nitrogen sources and the activating effect of tert-butyl hydroperoxide. The reaction was found to be efficient for the functionalization of mono-, di-, and trisubstituted olefins, and only a few functional groups are not tolerated. The alkyl azides obtained are versatile intermediates and can be transformed to the free amines or triazoles without isolation of the azides. Preliminary mechanistic investigations suggest a rate-limiting hydrocobaltation of the alkene, followed by an amination reaction. Radical intermediates cannot be ruled out and may be involved.
- Waser, Jerome,Gaspar, Boris,Nambu, Hisanori,Carreira, Erick M.
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p. 11693 - 11712
(2007/10/03)
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- Addition of arylboronic acids to symmetrical and unsymmetrical azo compounds
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(Chemical Equation Presented) The addition of aryl- and heteroarylboronic acids to azo compounds is described. Copper salt catalysis was necessary to perform the reaction under mild conditions and high yields. Excellent regioselectivity was observed in addition to unsymmetrical azo compounds.
- Kisseljova, Ksenija,Tsubrik, Olga,Sillard, Rannar,Maeeorg, Sirje,Maeeorg, Uno
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- Synthesis of N-propargylphenelzine and analogues as neuroprotective agents
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A series of N1- and N2-propargylphenelzine derivatives and analogues (1-7) was synthesized. In addition to their activity as monoamine oxidase inhibitors, two of the compounds, N1- and N2-propargylphenelzines (3 and 6), were found to be potent at preventing DSP-4-induced noradrenaline (NA) depletion in mouse hippocampus, suggesting that they have neuroprotective properties.
- Ling, Lei,Urichuk, Liana J.,Sloley,Coutts, Ronald T.,Baker, Glen B.,Shan, Jacqueline J.,Pang, Peter K.T.
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p. 2715 - 2717
(2007/10/03)
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- Herbicides
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Thiadiazabicyclooctanes and thiadiazabicyclooctenes of formula I STR1 wherein the substituents are as defined herein, having good pre- and post-emergence selective herbicidal properties.
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- Heteroaryliumthio substituted carbapenem derivatives: Synthesis and in vitro activity of 1β-methyl-2-(dihydropyrrolotriazoliumthio)carbapenems
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The syntheses of five thiols, including three dihydropyrrolotriazoliumthiol salts, 1,4-dimethyl-5-mercaptomethyl-1,2,4-triazolium trifluoromethanesulfonate, and 6-mercapto-6,7-dihydro-5h-pyrazolo[1,2-a][1,2,4]triazolium chloride; and the addition of these thiols to 4-nitrobenzyl (IR,5R,6S)-2-(diphenylphosphono)oxy-6-[1(R)-hydroxyethyl]-1-methylcarbapen-2-cm -3-carboxylate and the subsequent hydrogenolysis of the addition products is described. The latter thiol provides a new route towards the preparation of L-627 (LJC 10,627). The compounds were evaluated in vitro against a panel of Gram-positive and Gram-negative bacteria and their antibacterial activities compared with imipenem. The compounds were measured for their hydrolytic stability to dehydropeptidase I (DHP-I) relative to imipenem. The five compounds generally had poorer Gram-positive and Pseudomonas activity than imipenem, although their Gram negative activity was variably improved. The monocyclic triazolium analog was nearly comparable in overall activity to the four bicyclic heterarylium analogs evaluated, including L-627 (LJC 10,627), All compounds were more stable to DHP-I than imipenem, although minor differences existed among them.
- Wildonger,Ratcliffe
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p. 1866 - 1882
(2007/10/02)
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- Dithio and Thiono Esters, 56. - Reaction of Thio Esters and Thio Amides with Azodicarboxylic Acid Derivatives
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Dithio and thiono esters 1 react with azodicarboxylates 3 to form the addition products 4 or the oxidation products 5 in varying ratios.With malonates, malonamides and dithionomalonates only the addition products 7 were obtained.N,N,N',N'-Tetramethyldithiomalonamide yields with azodicarboxylic acid derivatives 3 either the normal addition product 8, the β-elimination product 9 or N,N,N',N'-tetramethyltrithiomesoxalamide (10A), the first stable vicinal trithiocarbonyl compound.Key Words: Dithio Esters / Thiono Esters / Thioamides / Azodicarboxylates / Azodicarboxamides / Trithiomesoxalamides
- Hartke, Klaus,Brutsche, Andreas,Gerber, H.-D.
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p. 927 - 932
(2007/10/02)
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- ENANTIOSPECIFIC AND DIASTEREOSELECTIVE SYNTHESIS OF ANTI α-HYDRAZINO- AND α-AMINO-β-HYDROXYACIDS THROUGH "ELECTROPHILIC AMINATION" OF β-HYDROXYESTERS
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β-Hydroxyesters 1a-d were transformed into corresponding dianions and condensed with di-t-butylazodicarboxylate to give anti protected α-hydrazino-β-hydroxyesters 2a-d with good diastereoselectivities (up to 94:6).Cleavage of protecting groups followed by ester hydrolysis gave the previously unknown anti α-hydrazino-β-hydroxyacids 4a-d, which were in turn converted by hydrogenolysis into anti α-amino-β-hydroxyacids 5a-d.Starting from (S) 1a, enantiomerically pure (2S,3S) allo-threonine 5a was obtained in good overall yields.On the contrary, reaction of silyl ketene acetal 10, derived from 1a, with a diazonium salt furnished predominantly the syn isomer, but in unsatisfactory yield.
- Guanti, Giuseppe,Banfi, Luca,Narisano, Enrica
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p. 5553 - 5562
(2007/10/02)
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