- Photo electron transfer induced desilylation of: N, N -bis(trimethylsilyl)aminodibenzoborole to aminodibenzoborole
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The synthesis of 9-amino-9-borafluorene is described using a photoinduced twofold desilylation of the N,N-bis(trimethylsilyl) derivative 2. The mechanistic analysis suggests an initial single electron transfer step from 2 to the halogen containing solvent. 9-Amino-9-borafluorene undergoes a photoinduced cyclooligomerization, most reasonably to the dimer.
- Keck, Constanze,Maichle-Mossmer, C?cilia,Bettinger, Holger F.
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- Coupling dinitrogen and hydrocarbons through aryl migration
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The activation of abundant molecules such as hydrocarbons and atmospheric nitrogen (N2) remains a challenge because these molecules are often inert. The formation of carbon–nitrogen bonds from N2 typically has required reactive organic precursors that are incompatible with the?reducing conditions that promote N2 reactivity1,?which has prevented catalysis. Here we report a diketiminate-supported iron system that sequentially activates benzene and N2 to form aniline derivatives. The key to this coupling reaction is the partial silylation of a reduced iron–dinitrogen complex, followed by migration?of a benzene-derived aryl group to the nitrogen. Further reduction releases N2-derived aniline, and the resulting iron species can re-enter the cyclic pathway. Specifically, we show that?an easily prepared diketiminate iron bromide complex2 mediates the one-pot conversion of several petroleum-derived arenes into the corresponding silylated aniline derivatives, by using a mixture of sodium powder, crown ether, trimethylsilyl bromide?and N2 as the nitrogen source. Numerous compounds along the cyclic pathway are isolated and crystallographically characterized, and their reactivity supports?a mechanism for sequential?hydrocarbon activation and N2 functionalization. This strategy couples?nitrogen atoms from N2 with abundant hydrocarbons, and maps a route towards future catalytic systems.
- McWilliams, Sean F.,Broere, Dani?l L. J.,Halliday, Connor J. V.,Bhutto, Samuel M.,Mercado, Brandon Q.,Holland, Patrick L.
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p. 221 - 226
(2020/08/19)
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- Metal-free deoxygenation and reductive disilylation of nitroarenes by organosilicon reducing reagents
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A metal-free deoxygenation and reductive disilylation of nitroarenes was achieved using N,N’-bis(trime-thylsilyl)-4,4’-bipyridinylidene (1) under mild and neutral reaction conditions, and a broad functional group tolerance was possible in this reaction. Mono-deoxygenation, giving a synthetically valuable N,O-bis(trimethylsilyl)phe-nylhydroxylamine (7a) as a readily available and safe phenylnitrene source from nitrobenzene, and double-deoxy-genation, giving N,N-bis(trimethylsilyl)anilines 8, were easily controlled by varying the amounts of 1 and reaction temperature as well as adding dibenzothiophene (DBTP). Reaction of 2-arylnitrobenzenes with 1 resulted in the formation of the corresponding carbazoles 14 via in situ-gen-erated phenylnitrene species derived by thermolysis of N,O-bis(trimethylsilyl)phenylhydroxylamines 7, followed by their subsequent intramolecular C H insertion. In addition, the intramolecular N N coupling reaction proceeded in the reduction of 2,2’-dinitrobiphenyl derivatives by 1, giving the corresponding benzo[c]cinnolines.
- Bhattacharjee, Argha,Hosoya, Hiromu,Ikeda, Hideaki,Nishi, Kohei,Tsurugi, Hayato,Mashima, Kazushi
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supporting information
p. 11278 - 11282
(2018/10/20)
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- Simple Nickel Salts for the Amination of (Hetero)aryl Bromides and Iodides with Lithium Bis(trimethylsilyl)amide
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Recent developments in the chemistry of C-N bond formation and the synthesis of anilines have allowed for the use of first-row transition metals to catalyze these transformations. Much of the progress in this area has been driven by comprehensive screening for privileged/tailored ligands, which can be costly and not readily available in a research laboratory setting. In this communication we report a protocol in which simple nickel salts catalyze the C-N cross-coupling reaction between (hetero)aryl bromides and iodides with lithium bis(trimethylsilyl)amide without the need for any additive ligand. This method is amenable to low nickel catalyst loadings (1%) as well as gram-scale reactions. Because of the good functional group tolerance and compatibility with heterocyclic moieties, this method is useful for academic laboratory settings where access to tailored ligands and noble-metal catalysts could be challenging.
- Martinez, Gabriel Espinosa,Nugent, Joseph W.,Fout, Alison R.
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supporting information
p. 2941 - 2944
(2018/09/21)
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- Peculiarities of the reaction of alkali metal bis(trimethylsilyl)amides with halobenzenes
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Lithium and sodium bis(trimethylsilyl)amides react with fluoro-, bromo-, and chlorobenzenes in THF or toluene to give a mixture of N,N-bis(trimethylsilyl)aniline and N,2-bis(trimethylsilyl)aniline. The latter compound is resulted from 1,3-shift of the trimethylsilyl group from nitrogen to ortho-carbon atom of the benzene ring. Effects of the solvent, halogen, and alkali metal nature as well as the reaction conditions on the ratio of isomers were examined. Reaction of iodobenzene with sodium bis(trimethylsilyl)amide in THF produces N,N-bis(trimethylsilyl)aniline and 2-iodo-N,N-bis(trimethylsilyl)aniline, while in toluene a mixture of three products, two indicated above and N,N-bis(trimethylsilyl)benzylamine, was obtained.
- Lis,Tsyrendorzhieva,Albanov,Gostevskii,Rakhlin
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p. 2090 - 2094
(2016/10/03)
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- A synthetic and mechanistic investigation into the cobalt(i) catalyzed amination of aryl halides
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Employing first-row transition metals in catalytic two-electron transformations remains a synthetic challenge. In order to overcome the common and often deleterious single-electron reactivity, an electron rich ligand was targeted on cobalt. Herein, we report the Co(i) catalyzed amination of aryl halides with lithium hexamethyldisilazide. This transformation features (PPh3)3CoCl (1) as the catalyst and affords structurally diverse and electronically varied primary arylamines in good chemical yields, with the scope of the reaction featuring arylamines that cannot be synthesized via traditional metal-catalyzed amination routes, including 4-aminophenylboronic acid pinacol ester. Stoichiometric reactivity revealed that (PPh3)2CoN(SiMe3)2 (2) is likely generated within the catalytic cycle and could be independently synthesized from the reaction of (PPh3)3CoCl with LiN(SiMe3)2. Catalytic reactivity featuring the Co-amide complex, (PPh3)2CoN(SiMe3)2, showed that it is a competent catalyst, implying that the (PPh3)3CoCl may be serving as a pre-catalyst in the reaction. Both stoichiometric and kinetic studies support the catalytic cycle involving a Co(i) complex. Catalytic reactions featuring Co(ii) complexes resulted in undesired biaryl formation, a product that is not observed under standard catalytic conditions and any productive catalytic reactivity likely arises from an in situ reduction of Co(ii) to Co(i). A Hammett study was carried out to differentiate between a closed-shell or radical mechanism, the results of which are consistent with the proposed closed-shell mechanism. Initial studies indicate that this reactivity may be expanded to other bulky nucleophiles. This journal is
- Brennan, Marshall R.,Kim, Dongyoung,Fout, Alison R.
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p. 4831 - 4839
(2015/02/19)
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- Migration of trimethylsilyl group in the reaction of sodium bis(trimethylsilyl)amide with bromobenzene
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The reaction of sodium bis(trimethylsilyl)amide with bromobenzene gave a mixture of N,N-bis-(trimethylsilyl)aniline and N,2-bis(trimethylsilyl)aniline, the latter being a rearrangement product formed via 1,3-migration of trimethylsilyl group from the nitrogen atom to the ortho-carbon atom in the benzene ring.
- Lis,Tsyrendorzhieva,Albanov,Rakhlin,Voronkov
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p. 1451 - 1453
(2014/01/06)
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- METHOD FOR THE PREPARATION OF A COMPOUND OF THE GENERAL FORMULA R1-R1 AND/OR R1-R2 USING HOMO AND HETERO COUPLING REACTIONS
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The present application relates to a method for the preparation of a compound of the general formula R1-R2 (I) and/or R1-R1 (II) comprising providing a compound of the general formula R1dM1Am.zM4Zn (III) or R1R2M1R3kAm.xM4Zn (IV) or R1M1R2R3kM2Am.xM4Zn (V) or R1M3R2M1.xM4Zn (VI) and reacting this compound III-VI with a quinone to produce a compound of the general formula (I) or (II) or a mixture of compounds (I) and (II). The coupling reaction can be used to prepare homo and/or hetero coupling products from well known starting materials using a quinone as redox reagent. The quinone may be recycled from the reaction.
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Page/Page column 5
(2010/11/29)
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- 1,2-Eliminations in a novel reductive coupling of nitroarenes to give azoxy arenes by sodium bis(trimethylsilyl)amide
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(Chemical Equation Presented) Symmetric azoxy arenes were successfully prepared in one step from 2 equiv of the corresponding nitroarenes by use of sodium bis-(trimethylsilyl)amide as the deoxygenating agents in THF at 150°C in a sealed tube.
- Jih, Ru Hwu,Das, Asish R.,Chia, Wei Yang,Huang, Jiann-Jyh,Hsu, Ming-Hua
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p. 3211 - 3214
(2007/10/03)
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- Efficient synthesis of 1,2,4-dithiazolidine-3,5-diones [dithiasuccinoyl- amines] from bis(chlorocarbonyl)disulfane plus bis(trimethylsilyl)amines
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The 1,2,4-dithiazolidine-3,5-dione heterocycle, also referred to as a dithiasuccinoyl (Dts)-amine, serves as a readily removable amino protecting group for building blocks used in syntheses of peptides, glycopeptides, and PNA; it is also useful as a masked isocyanate and (inversely) as a sulfurization reagent for trivalent phosphorus. Bis(chlorocarbonyl)disulfane, the two-sulfur analogue of succinyl chloride, has been envisioned as a reagent for facile single-step elaboration of the heterocycle. However, reactions of bis(chlorocarbonyl)disulfane directly with primary amines fail to yield Dts-amines for reasons that are discussed. Inspired by several precedents from the organosilicon chemistry literature that a trimethylsilyl group may serve as a "large proton," a successful, high-yield preparation of Dts-amines through reactions of bis(chlorocarbonyl)disulfane with bis(trimethylsilyl)amines has been developed. Studies aimed at elucidating mechanistic reasons for these observations are also presented. Copyright
- Barany, Michael J.,Hammer, Robert P.,Merrifield,Barany, George
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p. 508 - 509
(2007/10/03)
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- Palladium-catalyzed synthesis of arylamines from aryl halides and lithium bis(trimethylsilyl)amide as an ammonia equivalent
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(Equation presented) A simple, palladium-catalyzed method to convert aryl halides to the parent anilines using lithium bis(trimethylsilyl)amide (LiN(SiMe3)2) is reported. The reaction is catalyzed by Pd(dba)2 and P(t-Bu)3 and can be run with as little as 0.2 mol % of catalyst. The reaction is faster than competing generation of benzyne intermediates and, therefore, provides the aniline products regiospecifically.
- Lee, Sunwoo,Jorgensen, Morten,Hartwig, John F.
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p. 2729 - 2732
(2007/10/03)
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- Novel method for preparing bis(trimethylsilyl) amines via treatment with trimethylsilylamines and methyl iodide
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A convenient method for the synthesis of N,N-bis(trimethylsilyl)alkylamines has been reported. N-(Trimethylsilyl)diethylamine incorporated with a stoichiometric amount of methyl iodide was effective to convert primary amines, especially aromatic amines, and their monotrimethylsilyl derivatives into the corresponding N,N-bis(trimethylsilyl)amine derivatives in high yields. In the case of N-trimethylsilyl derivatives of aliphatic primary amines, a half-amount of silylamines served as a silylation agent against another half-amount of silylamines in the presence of 0.5 equivalent of methyl iodide to give N,N-bis(trimethylsilyl)alkylamines in good yield. Allyl iodide, allyl bromide and benzyl bromide were also effective to promote the silylation activity of silylamines.
- Hamada, Yoshitaka,Yamamoto, Yasushi,Shimizu, Hideaki
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- CONTRIBUTIONS TO THE CHEMISTRY OF ORGANIC SILICON-NITROGEN-COMPOUNDS, I. SYNTHESIS OF N,N-BIS-(TRIMETHYLSILYL)AMINES
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The preparation of N,N-bis-(trimethylsilyl)amines 1 has been investigated.Three convenient methods are reported: A, Transfer of (catalytically) activated Tms-groups to amines starting from N-silylated carbonamides, B, silylation of amines with trimethylsilylchloride 5/NEt3 in the presence of TiCl4, C, silylation of primary amines 4 or mono-(trimethylsilyl)amines 16 with CF3SO3 Tms/NEt3 or TmsI/NEt3.Methods A and B are limited to the silylation of (ar)alkylamines which have no branched α-position. Key words: N,N-bis-(trimethylsilyl)amines; N,N-bis-silylamines; N-silylcarbonamides.
- Schorr, Manfred,Schmitt, Wilfried
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- Novel Syntheses of Bis(trialkylsilyl)amines by Reductive Trialkylsilylation of Azo Compounds
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Reduction of azo compounds with a system of a trialkylchlorosilane and lithium has been found to afford bis(trialkylsilyl)amines in the presence of a transition metal halide as a catalyst in THF.The reaction course was significantly modified by using t-butyldimethylchlorosilane as a trialkylchlorosilane.
- Kira, Mitsuo,Nagai, Satoshi,Nishimura, Mitsushi,Sakurai, Hideki
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p. 153 - 156
(2007/10/02)
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