Reaction Of Dianion Research Articles

Adventures in 1,1-Diphenylacetone Dianion Chemistry

AbstractThe present personalized account highlights reactions of the dianion of 1,1-diphenylacetone and its applications. From a study directed towards the regioselectivity of such reactions a new allene synthesis via allene dianions was found by serendipity. In addition, reactions of allene dianions with various electrophiles have been studied.1 Introduction2 Cyclizations of the Dianion of 1,1-Diphenylacetone2.1 Reaction with Bis(cyclopentadienyl)zirconium Dichloride2.1 Reactions with Dichlorosilanes2.1 Reactions with Difluorosilanes2.1 Reactions with Ketones and Dielectrophiles3 Regioselectivity of Dianion Reactions4 Allene Dianions from Silyl Enol Ethers5 Scope of the Reactions of Allene Dianions6 Reactions of Allene Dianions with Ketones7 Reactions of Allene Dianions with Nitriles8 Conclusions

Synthetic and Structural Studies on Linear and Macrocyclic Pd- and Pt-Bridged Butterfly Fe/S Cluster Complexes

Three types of (diphosphine)Pd- or Pt-bridged butterfly Fe/S cluster complexes have been prepared by a simple and convenient one-pot synthetic method. The first type of such complexes involves the linear (diphosphine)Pd- or Pt-bridged double-butterfly Fe/S clusters [(μ-RS)(μ-S═CS)Fe2(CO)6]2[M(diphosphine)] (1–12; M = Pd and Pt; R = Et, t-Bu, Ph, and p-MeC6H4; diphosphine = dppe, dppv, and dppf), which were prepared by sequential reactions of monoanions [(μ-RS)(μ-CO)Fe2(CO)6]– (formed in situ from Fe3(CO)12, RSH, and Et3N) with excess CS2, followed by treatment of the resulting monoanions [(μ-RS)(μ-S═CS)Fe2(CO)6]– with (diphosphine)MCl2. The second type of complexes involves the macrocyclic (diphosphine)M-bridged double-butterfly Fe/S clusters [μ-S(CH2)4S-μ][(μ-S═CS)Fe2(CO)6]2[M(diphosphine)] (13–16; M = Pd and Pt; diphosphine = dppe and dppv), which were prepared by sequential reactions of dianion [{μ-S(CH2)4S-μ}{(μ-CO)Fe2(CO)6}2]2– (generated in situ from Fe3(CO)12, dithiol HS(CH2)4SH, and Et3N) with exc...

ChemInform Abstract: Recent Topics of the Metallacycles Composed of the Heavier Group 14 Elements

AbstractReview: [42 refs.

Structurally original oxathioethers macrocycles containing an exocyclic double-bond: synthesis, characterization, reactivity, and coordination

New oxathioethers macrocycles have been synthesized and characterized. Each macrocycle consists in structurally defined ether and thioether moieties and an exocyclic double-bond (2a–c) or a hydroxymethyl group (3a–c). Macrocycles (2a–c) have been synthesized by reaction of dianions of thioethers diols (1a–c) with 3-chloro-2-chloromethylprop-1-ene. Their hydroboration/oxidation led to corresponding primary alcohols (3a–c). Structures of compounds (2b) and (3a) have been determined by X-ray diffraction. The reactivity of the hydroxyl group allowed the preparation of oxathioethers macrocycles bearing a polyether chain or a benzyl group (4a,b) and the synthesis of new bicyclic sandwich-type compounds (5a,b). The ability of these functionalized macrocycles to coordinate to palladium has been investigated.

Reactivity indices as a measure of rate constants for protonation of radical anions and dianions

The DFT-based reactivity indices were used to describe protonation reactions of radical anions (RA) and dianions (DA) of aromatic compounds. A correlation between the experimental rate constants for protonation and the global reactivity indices was found. The indices were expressed through the electron affinities and ionization energies computed at the B3LYP level of theory. The protonation reactions of RA and DA of aromatic compounds are correctly described by the reactivity indices calculated as the inverse of the difference between the formal formation potential of RA (or DA) and the formal reduction potential of the proton donor.

ChemInform Abstract: A Protective Strategy in Carbene Complex Chemistry. Synthesis of Functionalized Fischer Carbene Complexes via Dianion Formation.

Anionic derivatives of Fischer-type carbene complexes (A and B) are stable toward strong bases and nucleophiles, and their organic moieties R and R 2 can be elaborated under strongly basic conditions to provide access to heteroaromatic and aliphatic carbene complexes bearing organic functional groups. The concept of anionic protection has been illustrated by the reactions of dianions 9 and 14 and the preparation of carbene complexes possessing up to four chiral centers. Some attempts to effect ortho lithiation of aromatic carbene complexes are also described

ChemInform Abstract: Unexpected Elimination to α,β-Alkynyl Ketones in the Reaction of Dianions of 1-Arylenaminones with Trimethylchlorosilane.

ChemInform Abstract: Unexpected Elimination to α,β-Alkynyl Ketones in the Reaction of Dianions of 1-Arylenaminones with Trimethylchlorosilane.

ChemInform Abstract: Reaction of Dianions of Acetoacetic Esters with Epibromohydrin Derivatives: A Novel Synthesis of Tetrahydrofuran Derivatives and Tetrahydropyran Derivatives.

Abstract The dianion of the acetoacetic ester reacts with epibromohydrin derivatives to afford a mixture of ( Z )-2-alkoxycarbonylmethylidenetetrahydrofuran derivative and ( E )-2-alkoxycarbonylmethylidenetetrahydropyran derivative. The selective formation of the tetrahydrofuran derivative is achieved by the use of LiClO 4 as the additive.

Unsaturated sulfur compounds from reactions of lithiated methylazines with carbon disulfide and electrophiles

2-Methylpyridine (1a), 2,6-dimethylpyridine (1b), 2-methylpyrazine (1c) and 2-methylquinoline (1d) were treated with lithium diisopropylamide (LDA) in THF at low temperature followed by carbon disulfide to give the dianion (5). Reactions of dianion (5) with iodomethane, 1,2-dibromoethane, ethyl chloroacetate, α -chloroacetonitrile or phenacyl bromide gave 6a–c, 6e, 9, 10, 11, 12 and 13, respectively. Reactions of dianion (5) with 1,2-dibromoethene gave the dithiocarboxylic acids (14a–c) rather than a dithiolene, and reaction of dianion (5a) with aqueous ammonium persulfate gave 15. Treatment of 2-methylpyridine (1a) with lithium diisopropylamide (LDA) and 2-bromopyridine afforded tetra-2-pyridylmethane (18) as the main product.

Reductive activation of arenes 22. Reactions of the terephthalonitrile radical anion and dianion with α,ω-dibromoalkanes. New evidence for the charge transfer complex as a key intermediate in the reactions of the dianion

The major products of reactions of the terephthalonitrile radical anion with α,ω-dibromoalkanes Br(CH2)nBr (n = 3–5) were 4-(ω-bromoalkyl)benzonitriles. Analogous reactions of the terephthalonitrile dianion mainly yielded α,ω-bis(4-cyanophenyl)alkanes. Both transformations are convenient one-step routes to otherwise not easily accessible compounds that are valuable as versatile building blocks. The results of alkylation allow one to suggest that reactions of the dianion with intermediate 4-(ω-bromoalkyl)benzonitriles proceed more rapidly than those with the starting α,ω-dibromoalkanes. This was confirmed by competitive reactions of the dianion with 4-(ω-bromoalkyl)benzonitriles and the corresponding alkyl bromides. To explain such a ratio of the reaction rates, a mechanism was proposed for the reaction of the dianion with 4-(ω-bromoalkyl)benzonitriles. According to this mechanism, a charge transfer complex is a key reaction intermediate.

Cyclization Reactions of Dianions in Organic Synthesis

AbstractFor Abstract see ChemInform Abstract in Full Text.

Cyclization reactions of dianions in organic synthesis.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCyclization Reactions of Dianions in Organic Synthesis†Peter Langer and Walter FreibergView Author Information Institut für Chemie und Biochemie der Ernst-Moritz-Arndt Universität Greifswald, Soldmannstrasse 16, 17487 Greifswald, Germany Cite this: Chem. Rev. 2004, 104, 9, 4125–4150Publication Date (Web):August 21, 2004Publication History Received17 February 2004Published online21 August 2004Published inissue 1 September 2004https://doi.org/10.1021/cr010203lCopyright © 2004 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views2618Altmetric-Citations124LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (649 KB) Get e-AlertsSUBJECTS:Anions,Cyclization,Ethyl groups,Hydrocarbons,Ketones Get e-Alerts

Syntheses and catalytic properties of polystyrene supported nickel(II) carborane complexes

1-Methyl- and 1-phenyl- ortho-carborane functionalized polystyrenes ( 1a, 1b) were synthesized by the reactions of pertinent carborane lithium salts and Merrifield’s peptide resin (1%), in refluxing tetrahydrofuran (THF) solvent in 90 and 85% yield, respectively. Further reaction of dianions derived from the resulting 1a and 1b with dichloro bis(triphenylphosphine)nickel(+II) produced novel polystyrene supported neutral nickel(+II) carborane compounds ( 2a, 2b). The polyethylene, polystyrene and polyvinyl chloride catalytic properties of the nickel complexes in THF and ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF 4], of compounds 2a and 2b were tested.

Syntheses of Examples of the 5,6-dihydro-4H-[1,2,3]triazolo[4,5,1-ij]quinoline, 4,5,6,7-tetrahydro[1,2,3]triazolo[4,5,1-jk][1,4]benzodiazepine, and 5,6,7,8-tetrahydro-4H-[1,2,3]triazolo[4,5,1-kl][1]benzazocine ring systems.

Lithiation of 1-vinylbenzotriazole 9 with n-BuLi (2 equiv) generates dianion 10, which upon subsequent reaction with 1,2- and 1,4-diketones affords 14 and 13, representatives of the 5,6-dihydro-4H-[1,2,3]triazolo[4,5,1-ij]quinoline 1 and 5,6,7,8-tetrahydro-4H-[1,2,3]triazolo[4,5,1-kl][1]benzazocine 2 ring systems, respectively. Reactions of dianion 10 with isocyanates give 15a,b, which contain the 4,5,6,7-tetrahydro[1,2,3]triazolo[4,5,1-jk][1,4]benzodiazepine 3 ring system.

Reaction of Functionalized Organolithium Compounds with Substituted Oxiranes: Useful Methodology for 1,6‐ and 1,7‐Diols, and Tetrahydrobenzoxepines.

Abstract The reaction of dianions 2 , derived from the reductive opening of phthalan ( 1a ) or isochroman ( 1b ) with lithium and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB) at 0°C, with several epoxides 3 at the same temperature gave, after hydrolysis, 1,6- and 1,7-diols, respectively. Dehydration of 1,6-diols by treatment with BF3·OEt2 in dichloromethane at temperatures ranging from −30 to 20°C gave tetrahydrobenzoxepines 5 in very good yields. Under the same reaction conditions 1,7-diols 4 did not undergo dehydration.

Formation and chemical reactivities of a new type of double-butterfly [[Fe2(mu-CO)(CO)6]2(mu-SZS-mu)]2-: synthetic and structural studies on novel linear and macrocyclic butterfly Fe/E (E=S, Se) cluster complexes.

A new type of double-butterfly [[Fe(2)(mu-CO)(CO)(6)](2)(mu-SZS-mu)](2-) (3), a dianion that has two mu-CO ligands, has been synthesized from dithiol HSZSH (Z=(CH(2))(4), CH(2)(CH(2)OCH(2))(1-3)CH(2)), [Fe(3)(CO)(12)], and Et(3)N in a molar ratio of 1:2:2 at room temperature. Interestingly, the in situ reactions of dianions 3 with various electrophiles affords a series of novel linear and macrocyclic butterfly Fe/E (E=S, Se) cluster complexes. For instance, while reactions of 3 with PhC(O)Cl and Ph(2)PCl give linear clusters [[Fe(2)(mu-PhCO)(CO)(6)](2)(mu-SZS-mu)] (4 a,b: Z=CH(2)(CH(2)OCH(2))(2,3)CH(2)) and [[Fe(2)(mu-Ph(2)P)(CO)(6)](2)(mu-SZS-mu)] (5 a,b: Z=CH(2)(CH(2)OCH(2))(2,3)CH(2)), reactions with CS(2) followed by treatment with monohalides RX or dihalides X-Y-X give both linear clusters [[Fe(2)(mu-RCS(2))(CO)(6)](2)(mu-SZS-mu)] (6 a-e: Z=CH(2)(CH(2)OCH(2))(1,2)CH(2); R=Me, PhCH(2), FeCp(CO)(2)) and macrocyclic clusters [[Fe(2)(CO)(6)](2)(mu-SZS-mu)(mu-CS(2)YCS(2)-mu)] (7 a-e: Z=(CH(2))(4), CH(2)(CH(2)OCH(2))(1-3)CH(2); Y=(CH(2))(2-4), 1,3,5-Me(CH(2))(2)C(6)H(3), 1,4-(CH(2))(2)C(6)H(4)). In addition, reactions of dianions 3 with [Fe(2)(mu-S(2))(CO)(6)] followed by treatment with RX or X-Y-X give linear clusters [[[Fe(2)(CO)(6)](2)(mu-RS)(mu(4)-S)](2)(mu-SZS-mu)] (8 a-c: Z=CH(2)(CH(2)OCH(2))(1,2)CH(2); R=Me, PhCH(2)) and macrocyclic clusters [[[Fe(2)(CO)(6)](2)(mu(4)-S)](2)(mu-SYS-mu)(mu-SZS-mu)] (9 a,b: Z=CH(2)(CH(2)OCH(2))(2,3)CH(2); Y=(CH(2))(4)), and reactions with SeCl(2) afford macrocycles [[Fe(2)(CO)(6)](2)(mu(4)-Se)(mu-SZS-mu)] (10 d: Z=CH(2)(CH(2)OCH(2))(3)CH(2)) and [[[Fe(2)(CO)(6)](2)(mu(4)-Se)](2)(mu-SZS-mu)(2)] (11 a-d: Z=(CH(2))(4), CH(2)(CH(2)OCH(2))(1-3)CH(2)). Production pathways have been suggested; these involve initial nucleophilic attacks by the Fe-centered dianions 3 at the corresponding electrophiles. All the products are new and have been characterized by combustion analysis and spectroscopy, and by X-ray diffraction techniques for 6 c, 7 d, 9 b, 10 d, and 11 c in particular. X-ray diffraction analyses revealed that the double-butterfly cluster core Fe(4)S(2)Se in 10 d is severely distorted in comparison to that in 11 c. In view of the Z chains in 10 a-c being shorter than the chain in 10 d, the double cluster core Fe(4)S(2)Se in 10 a-c would be expected to be even more severely distorted, a possible reason for why 10 a-c could not be formed.

Reaction of functionalized organolithium compounds with substituted oxiranes: useful methodology for 1,6- and 1,7-diols, and tetrahydrobenzoxepines

The reaction of dianions 2 , derived from the reductive opening of phthalan ( 1a ) or isochroman ( 1b ) with lithium and a catalytic amount of 4,4′-di- tert-butylbiphenyl (DTBB) at 0°C, with several epoxides 3 at the same temperature gave, after hydrolysis, 1,6- and 1,7-diols, respectively. Dehydration of 1,6-diols by treatment with BF 3·OEt 2 in dichloromethane at temperatures ranging from −30 to 20°C gave tetrahydrobenzoxepines 5 in very good yields. Under the same reaction conditions 1,7-diols 4 did not undergo dehydration.

Synthesis of Bis- and Tris(indolinylidenemethyl)benzenes by One-Pot Reactions of Polylithiated Nitriles with Bis(imidoyl)chlorides of Oxalic Acid

The reaction of polylithiated di- and tricyanomethylbenzenes with oxalic acid-bis(imidoyl)chlorides afforded novel oligo(indolinylidenemethyl)benzenes with the formation of up to six carbon-carbon bonds. The UV/Vis spectroscopic features of these and related compounds were studied. 1,4-Disubstituted benzenes containing a large π-system have been efficiently prepared by the reaction of dianions with 1,4-dicyanobenzene. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).

Chemistry of ketone α,β-dianions. Acylation reactions of dianion cuprates by acid chlorides

The cross-coupling reaction of dianion cuprates, generated from ketone α,β-dianions and copper salts, with acid chlorides, was studied. The reaction gave good to moderate yields of unsymmetrical 1,4-diketones. The consecutive treatment of a dianion cuprate with cyclohexanecarbonyl chloride and methyl iodide or two different acid chlorides gave 2-methyl-substituted 1,4-diketone or triketone, respectively.

Synthesis, characterization and reactions of cluster complexes containing SeRuCoM (M=Mo or W) core and a functionally substituted cyclopentadienyl ligand

Reactions of monoanions {M(CO) 3[η 5-C 5H 4C(O)CH 2CH 2CO 2Me]} − with RuCo 2(CO) 9(μ 3-Se) in THF at 60°C gave two new cluster derivatives (μ 3-Se)CoMRu(CO) 8[η 5-C 5H 4C(O)CH 2CH 2CO 2Me] (M=Mo 1, M=W 2). Similarly, reactions of dianions −{M(CO) 3[(η 5-C 5H 4)C(O)CH 2CH 2C(O)(η 5-C 5H 4)](CO) 3M} − with two molecules of RuCo 2(CO) 9(μ 3-Se) gave 1,4-succinoyl(biscyclopentadienyl)-bridged double cluster complexes (μ 3-Se)CoMRu(CO) 8[(η 5-C 5H 4)C(O)CH 2CH 2C(O)(η 5-C 5H 4)]CoMRu(CO) 8(μ 3-Se) (M=Mo 3, M=W 4). Treatment of cluster (μ 3-Se)CoMoRu(CO) 8[(η 5-C 5H 4)C(O)Me] with ammine derivatives 2,4-dinitrophenylhydrazine, NH 2NHC(S)NH 2, (−)-5-(α-phenyl)semioxamazide and l-(+)-menthydrazide, respectively, at room temperature produced four new hydrazone cluster derivatives (μ 3-Se)CoMoRu(CO) 8[η 5-C 5H 4C(NR)Me] (R=NHC 6H 3-2,4-(NO 2) 2 5, R=NHC(S)NH 2 6, R=NHC(O)C(O)NHCH(Me)(C 6H 5) 7, R=NHCO 2-menthyl 8). However, cluster 1 can only react with 2,4-dinitrophenylhydrazine to give the formation of cluster (μ 3-Se)CoMoRu(CO) 8[η 5-C 5H 4C(NR)CH 2CH 2CO 2Me] (R=NHC 6H 3-2,4-(NO 2) 2 9) under similar condition. Although, two kinds of optically active groups have been introduced into cluster (μ 3-Se)CoMoRu(CO) 8[(η 5-C 5H 4)C(O)Me], the mixture of diastereoisomers could not be separated by silica gel chromatography. The 13C-NMR spectra showed the presence of a pair of diastereoisomers.