17777-31-0Relevant articles and documents
Air-Stable Iron-Based Precatalysts for Suzuki-Miyaura Cross-Coupling Reactions between Alkyl Halides and Aryl Boronic Esters
Wong, Alexander S.,Zhang, Bufan,Li, Bo,Neidig, Michael L.,Byers, Jeffery A.
, p. 2461 - 2472 (2021/11/01)
The development of an air-stable iron(III)-based precatalyst for the Suzuki-Miyaura cross-coupling reaction of alkyl halides and unactivated aryl boronic esters is reported. Despite benefits to cost and toxicity, the proclivity of iron(II)-based complexes to undergo deactivationviaoxidation or hydrolysis is a limiting factor for their widespread use in cross-coupling reactions compared to palladium-based or nickel-based complexes. The new octahedral iron(III) complex demonstrates long-term stability on the benchtop as assessed by a combination of1H NMR spectroscopy, M?ssbauer spectroscopy, and its sustained catalytic activity after exposure to air. The improved stability of the iron-based catalyst facilitates an improved protocol in which Suzuki-Miyaura cross-coupling reactions of valuable substrates can be assembled without the use of a glovebox and access a diverse scope of products similar to reactions assembled in the glovebox with iron(II)-based catalysts.
Nickel-Catalyzed Migratory Hydrocyanation of Internal Alkenes: Unexpected Diastereomeric-Ligand-Controlled Regiodivergence
Gao, Jihui,Jiao, Mingdong,Ni, Jie,Yu, Rongrong,Cheng, Gui-Juan,Fang, Xianjie
supporting information, p. 1883 - 1890 (2020/12/01)
A regiodivergent nickel-catalyzed hydrocyanation of a broad range of internal alkenes involving a chain-walking process is reported. When appropriate diastereomeric biaryl diphosphite ligands are applied, the same starting materials can be converted to either linear or branched nitriles with good yields and high regioselectivities. DFT calculations suggested that the catalyst architecture determines the regioselectivity by modulating electronic and steric interactions. In addition, moderate enantioselectivities were observed when branched nitriles were produced.
A General Organocatalytic System for Electron Donor-Acceptor Complex Photoactivation and Its Use in Radical Processes
De Pedro Beato, Eduardo,Melchiorre, Paolo,Spinnato, Davide,Zhou, Wei
supporting information, p. 12304 - 12314 (2021/08/20)
We report herein a modular class of organic catalysts that, acting as donors, can readily form photoactive electron donor-acceptor (EDA) complexes with a variety of radical precursors. Excitation with visible light generates open-shell intermediates under mild conditions, including nonstabilized carbon radicals and nitrogen-centered radicals. The modular nature of the commercially available xanthogenate and dithiocarbamate anion organocatalysts offers a versatile EDA complex catalytic platform for developing mechanistically distinct radical reactions, encompassing redox-neutral and net-reductive processes. Mechanistic investigations, by means of quantum yield determination, established that a closed catalytic cycle is operational for all of the developed radical processes, highlighting the ability of the organic catalysts to turn over and iteratively drive every catalytic cycle. We also demonstrate how the catalysts' stability and the method's high functional group tolerance could be advantageous for the direct radical functionalization of abundant functional groups, including aliphatic carboxylic acids and amines, and for applications in the late-stage elaboration of biorelevant compounds and enantioselective radical catalysis.
Photoinduced 1,2-Hydro(cyanomethylation) of Alkenes with a Cyanomethylphosphonium Ylide
Miura, Tomoya,Moriyama, Daisuke,Funakoshi, Yuuta,Murakami, Masahiro
supporting information, p. 511 - 514 (2019/02/26)
An efficient method has been developed for the 1,2-hydro(cyanomethylation) of alkenes, in which a cyanomethyl radical species is generated from a cyanomethylphosphonium ylide by irradiation with visible light in the presence of an iridium complex, a thiol, and ascorbic acid. The cyanomethyl radical species then adds across the C=C double bond of an alkene to form an elongated alkyl radical species that accepts a hydrogen atom from the thiol to produce an elongated aliphatic nitrile. The ascorbic acid acts as the reductant to complete the catalytic cycle.
Cooperative Palladium/Lewis Acid-Catalyzed Transfer Hydrocyanation of Alkenes and Alkynes Using 1-Methylcyclohexa-2,5-diene-1-carbonitrile
Bhunia, Anup,Bergander, Klaus,Studer, Armido
supporting information, p. 16353 - 16359 (2018/11/25)
Catalytic transfer hydrocyanation represents a clean and safe alternative to hydrocyanation processes using toxic HCN gas. Such reactions provide access to pharmaceutically important nitrile derivatives starting with alkenes and alkynes. Herein, an efficient and practical cooperative palladium/Lewis acid-catalyzed transfer hydrocyanation of alkenes and alkynes is presented using 1-methylcyclohexa-2,5-diene-1-carbonitrile as a benign and readily available HCN source. A large set of nitrile derivatives (>50 examples) are prepared from both aliphatic and aromatic alkenes with good to excellent anti-Markovnikov selectivity. A range of aliphatic alkenes engage in selective hydrocyanation to provide the corresponding nitriles. The introduced method is useful for chain walking hydrocyanation of internal alkenes to afford terminal nitriles in good regioselectivities. This protocol is also applicable to late-stage modification of bioactive molecules.
Expedient iron-catalyzed coupling of alkyl, benzyl and allyl halides with arylboronic esters
Bedford, Robin B.,Brenner, Peter B.,Carter, Emma,Carvell, Thomas W.,Cogswell, Paul M.,Gallagher, Timothy,Harvey, Jeremy N.,Murphy, Damien M.,Neeve, Emily C.,Nunn, Joshua,Pye, Dominic R.
supporting information, p. 7935 - 7938 (2014/07/07)
While attractive, the iron-catalyzed coupling of arylboron reagents with alkyl halides typically requires expensive or synthetically challenging diphosphine ligands. Herein, we show that primary and secondary alkyl bromides and chlorides, as well as benzyl and allyl halides, can be coupled with arylboronic esters, activated with alkyllithium reagents, by using very simple iron-based catalysts. The catalysts used were either adducts of inexpensive and widely available diphosphines or, in a large number of cases, simply [Fe(acac)3] with no added co- ligands. In the former case, preliminary mechanistic studies highlight the likely involvement of iron(I)-phosphine intermediates. More irons in the fire: Primary and secondary alkyl, benzyl and allyl halides were coupled with arylboronic esters by using very simple iron-based catalysts. These were either adducts of inexpensive and widely available diphosphines or, in a large number of cases, simply [Fe(acac)3] with no added co-ligands (see scheme; acac=acetylacetonate). In the former case, preliminary mechanistic studies highlight the likely involvement of low-coordinate iron(I)-phosphine intermediates.
Copper-catalyzed cross-coupling reaction of organoboron compounds with primary alkyl halides and pseudohalides
Yang, Chu-Ting,Zhang, Zhen-Qi,Liu, Yu-Chen,Liu, Lei
, p. 3904 - 3907 (2011/05/15)
Non-activated alkyl electrophiles, including alkyl iodides, bromides, tosylates, mesylates, and even chlorides, underwent copper-catalyzed cross-coupling with aryl boron compounds and alkyl 9-BBN reagents (see scheme; 9-BBN=9-borabicyclo[3.3.1]nonane). The reactions proceed with practically useful reactivities and thus complement palladium- and nickel-catalyzed Suzuki-Miyaura coupling reactions of alkyl halides.
Monoalkylation of acetonitrile by primary alcohols catalyzed by iridium complexes
Anxionnat, Bruno,Gomez Pardo, Domingo,Ricci, Gino,Cossy, Janine
supporting information; experimental part, p. 4084 - 4087 (2011/09/21)
The monoalkylation of acetonitrile by primary alcohols was achieved in a one-pot sequence in the presence of iridium catalysts. A diversity of nitriles has been obtained from aryl- and alkyl-methanols in excellent yield.
Air-stable secondary phosphine oxide or chloride (Pre)ligands for cross-couplings of unactivated alkyl chlorides
Ackermann, Lutz,Kapdi, Anant R.,Schulzke, Carola
supporting information; experimental part, p. 2298 - 2301 (2010/08/05)
In situ generated and crystallographically well-defined, isolated palladium complexes derived from seven novel air-stable secondary phosphine oxides or chlorides enabled challenging Kumada-Corriu cross-couplings of unactivated alkyl chlorides bearing β-hy
Room-temperature Hiyama cross-couplings of arylsilanes with alkyl bromides and iodides
Lee, Jae-Young,Fu, Gregory C.
, p. 5616 - 5617 (2007/10/03)
The first method for achieving Hiyama couplings of unactivated alkyl bromides and iodides is reported. The desired carbon-carbon bond formation proceeds under mild conditions (room temperature) with good functional-group tolerance. Copyright
