ConspectusSingle electron oxidation of amines provides an efficient way to access synthetically useful α-aminoalkyl radicals as reactive intermediates. After the single amines, fragmentation resulting radical cations proceeds give along with generation a proton. In synthetic utilization radicals, precise control transfer is essential, because further occurs more easily than starting and are converted into corresponding iminium ions. As result, photoinduced quite attractive in...

Synthetic use of α-aminoalkyl radicals formed by single electron oxidation amines is quite limited. Here we demonstrate addition to electron-deficient alkenes visible-light-mediated transfer using transition metal polypyridyl complexes as photocatalysts, via a sequential redox pathway.

Abstract Synthesis and reactivity of iron-dinitrogen complexes have been extensively studied, because the iron atom plays an important role in industrial biological nitrogen fixation. As a result, iron-catalyzed reduction molecular dinitrogen into ammonia has recently achieved. Here we show that complex bearing anionic PNP-pincer ligand works as effective catalyst towards catalytic fixation, where mixture hydrazine is produced. In present reaction system, catalytically directly converted by...

Abstract Intensive efforts for the transformation of dinitrogen using transition metal–dinitrogen complexes as catalysts under mild reaction conditions have been made. However, limited systems succeeded in catalytic formation ammonia. Here we show that newly designed and prepared dinitrogen-bridged dimolybdenum bearing N -heterocyclic carbene- phosphine-based PCP-pincer ligands [{Mo(N 2 ) (PCP)} (μ-N )] ( 1 work so far most effective towards ammonia from ambient conditions, where up to 230...

Recent advances in the transition-metal-catalyzed enantioselective propargylic substitution reactions of alcohol derivatives with nucleophiles are reviewed this article. After disclosure first example a ruthenium-catalyzed alkylation, various types reactions, including propargylation aromatic compounds, have been reported last eight years. In addition, variety alkylations use two distinct catalysts, where catalysts work cooperatively to promote asymmetric reactions.

Newly designed and prepared molybdenum–nitride complexes bearing a mer-tridentate triphosphine as ligand have been found to work the most effective catalysts toward catalytic reduction of dinitrogen ammonia under ambient conditions, where up 63 equiv based on Mo atom catalyst were produced.

This paper describes our recent progress in catalytic nitrogen fixation by using transition-metal-dinitrogen complexes as catalysts. Two reaction systems for the transformation of molecular dinitrogen into ammonia and its equivalent such silylamine under ambient conditions have been achieved molybdenum-, iron-, cobalt-dinitrogen Many new findings presented here may provide access to development economical place Haber-Bosch process.

A series of dinitrogen-bridged dimolybdenum-dinitrogen complexes bearing 4-substituted PNP-pincer ligands are synthesized by the reduction corresponding molybdenum trichloride under 1 atm molecular dinitrogen. In accordance with a theoretical study, catalytic activity is enhanced introduction an electron-donating group to pyridine ring ligand, and complex 4-methoxy-substituted found work as most effective catalyst, where 52 equiv ammonia produced based on catalyst (26 each atom catalyst),...

ConspectusNitrogen fixation is an essential chemical process both biologically and industrially. Since the discovery of first transition-metal–dinitrogen complex in 1965, a great deal effort has been devoted to development artificial nitrogen systems that work under mild reaction conditions. However, transformation chemically inert dinitrogen using homogeneous catalysts still challenging because difficulty breaking strong triple bond dinitrogen, very limited number transition metal complexes...

Abstract The direct formation of ammonia from molecular dinitrogen under mild reaction conditions was achieved by using new cobalt complexes bearing an anionic PNP‐type pincer ligand. Up to 15.9 equivalents were produced based on the amount catalyst together with 1.0 equivalent hydrazine (17.9 equiv fixed nitrogen atoms).

Abstract We have now found that molybdenum–iodide complexes bearing a PNP-pincer ligand higher catalytic activity than the so far reported molybdenum–dinitrogen for ammonia formation from nitrogen gas under ambient reaction conditions, up to 830 equiv being produced based on dinitrogen-bridged dimolybdenum complex (415 of molybdenum atom). This remarkable is induced by novel pathway, where generation dimolybdenum–iodide key point promote direct cleavage nitrogen–nitrogen triple bond bridging...

Abstract A combination of nickel and photoredox catalysts promoted novel cross‐coupling reactions aryl halides with 4‐alkyl‐1,4‐dihydropyridines. 4‐Alkyl‐1,4‐dihydropyridines act as formal nucleophilic alkylation reagents through a photoredox‐catalyzed carbon–carbon (C−C) bond‐cleavage process. The present strategy provides an alternative to classical carbon‐centered nucleophiles, such organometallic reagents.

Abstract Mechanistic insight into the catalytic production of ammonia from dinitrogen is needed to improve synthesis this vital molecule. Here we study use samarium diiodide (SmI 2 ) and water in presence molybdenum complexes that bear PCP-type pincer ligands synthesize ammonia. The proton-coupled electron transfer during formation a N–H bond on imide complex was found be rate-determining step at high catalyst concentrations. Additionally, dimerization became low We designed with various...

Abstract In sharp contrast to the well‐established transition metal‐ catalyzed allylic substitution reactions, study of corresponding propargylic reactions has been quite limited for constructing carbon–carbon and carbon–heteroatom bonds at position. However, during last decade, general useful catalytic have developed extensively. this Review, we summarize recent advances in alcohols their derivatives with heteroatom‐ carbon‐centered nucleophiles. addition a variety metals, such as Ru, Re,...

The scope and limitations of the copper-catalyzed propargylic amination various esters with amines are presented, where optically active diphosphines such as Cl-MeO-BIPHEP BINAP work good chiral ligands. A variety secondary available nucleophiles for this catalytic reaction to give corresponding a high enantioselectivity. results some stoichiometric reactions indicate that proceeds via copper−allenylidene complexes formed in situ, attack electrophilic γ-carbon atom allenylidene complex is an...

Flexing your bipheps: Enantioselective propargylic substitution reactions of acetates with amines catalyzed by a copper-(R)-Cl-MeO-biphep or -binap complex give the corresponding in excellent yields up to 89 % ee. The reaction described may provide novel synthetic method for preparation chiral amines. Supporting information this article is available on WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z800276_s.pdf from author. Please note: publisher not responsible content...

Highly diastereoselective ortho-lithiation (84-99% de) of chiral oxazolinylferrocenes followed by quenching with an electrophile such as MeI, PPh2Cl or (PhSe)2 leading to the corresponding ortho-substituted ferrocenes is accomplished. The molecular structure a phenylseleno-substituted compound, fully characterized X-ray crystallography, showed attack from unexpected site.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTNovel Propargylic Substitution Reactions Catalyzed by Thiolate-Bridged Diruthenium Complexes via Allenylidene IntermediatesYoshiaki Nishibayashi, Issei Wakiji, and Masanobu HidaiView Author Information Department of Chemistry Biotechnology Graduate School Engineering, The University Tokyo Hongo, Bunkyo-ku, 113-8656, Japan Cite this: J. Am. Chem. Soc. 2000, 122, 44, 11019–11020Publication Date (Web):October 21, 2000Publication History...

Treatment of the tungsten dinitrogen complex cis-[W(N2)2(PMe2Ph)4] (Me = methyl, Ph phenyl) with an equilibrium mixture [RuCl(dppp)2]X and trans-[RuCl(eta2-H2)(dppp)2]X [X BF4, PF6, or OSO2CF3; dppp 1,3-bis(diphenylphosphino)propane] under 1 atmosphere dihydrogen at 55 degrees Celsius for 24 hours gave NH3 in moderate yield. The same reaction presence acetone produced azine high None these reactions proceeded absence dihydrogen.

It is vital to design effective nitrogen fixation systems that operate under mild conditions, and this end we recently reported an example of the catalytic formation ammonia using a dinitrogen-bridged dimolybdenum complex bearing pincer ligand, where up twenty three equivalents were produced based on catalyst. Here study origin behaviour ligand with density functional theory calculations, stoichiometric from molecular dinitrogen ambient conditions. Comparison di- mono-molybdenum shows core...