16424-56-9Relevant articles and documents
Ligand-Controlled Regiodivergence in Nickel-Catalyzed Hydroarylation and Hydroalkenylation of Alkenyl Carboxylic Acids**
Deng, Ruohan,Engle, Keary M.,Fu, Yue,Gao, Yang,Li, Zi-Qi,Liu, Peng,Tran, Van T.
supporting information, p. 23306 - 23312 (2020/10/19)
A nickel-catalyzed regiodivergent hydroarylation and hydroalkenylation of unactivated alkenyl carboxylic acids is reported, whereby the ligand environment around the metal center dictates the regiochemical outcome. Markovnikov hydrofunctionalization products are obtained under mild ligand-free conditions, with up to 99 % yield and >20:1 selectivity. Alternatively, anti-Markovnikov products can be accessed with a novel 4,4-disubstituted Pyrox ligand in excellent yield and >20:1 selectivity. Both electronic and steric effects on the ligand contribute to the high yield and selectivity. Mechanistic studies suggest a change in the turnover-limiting and selectivity-determining step induced by the optimal ligand. DFT calculations reveal that in the anti-Markovnikov pathway, repulsion between the ligand and the alkyl group is minimized (by virtue of it being 1° versus 2°) in the rate- and regioselectivity-determining transmetalation transition state.
Rhodium-catalyzed asymmetric hydroboration of γ,δ-unsaturated amide derivatives: δ-borylated amides
Hoang,Zhang,Takacs
supporting information, p. 4838 - 4841 (2018/05/23)
γ,δ-Unsaturated amides in which the alkene moiety bears an aryl or heteroaryl substituent undergo regioselective rhodium-catalyzed δ-borylation by pinacolborane to afford chiral secondary benzylic boronic esters. The results contrast the γ-borylation of γ,δ-unsaturated amides in which the disubstituted alkene moiety bears only alkyl substituents; the reversal in regiochemistry is coupled with a reversal in the sense of π-facial selectivity.
Aminolithiation–arylation consecutive cyclization of N-(2-fluorophenyl)methylaminoalkylstyryls giving aryl-substituted pyrido[1,2-b]isoquinolines
Yamamoto, Yasutomo,Nakanishi, Yasue,Yamada, Ken-ichi,Tomioka, Kiyoshi
supporting information, p. 5309 - 5318 (2018/06/11)
Aminolithiation–arylation tandem cyclization of N-(2-fluorophenyl)methylaminoalkylstyryls proceeded smoothly to give hexahydro-2H-pyrido[1,2-b]isoquinoline using a stoichiometric amount of n-BuLi with high trans selectivity. The arylation reaction was highly accelerated by the addition of HMPA. Both pyrido- and pyrrolo-[1,2-b]isoquinoline were successfully constructed by this tandem reaction.
CARBOXAMIDE INHIBITORS
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Paragraph 0392-0394, (2017/08/01)
The present invention provides a compound of formula I The compounds of formula I demonstrate properties as Smurf-1 inhibitors and are thus useful in the treatment of a range of disorders, particularly pulmonary arterial hypertension.
Safe and reliable synthesis of diazoketones and quinoxalines in a continuous flow reactor
Martin, Laetitia J.,Marzinzik, Andreas L.,Ley, Steven V.,Baxendale, Ian R.
supporting information; experimental part, p. 320 - 323 (2011/03/23)
A flow method for the synthesis of aliphatic and aromatic diazoketones from acyl chloride precursors has been developed and used to prepare quinoxalines in a multistep sequence without isolation of the potentially explosive diazoketone. The protocol showcases an efficient in-line purification using supported scavengers with time-saving and safety benefits and in particular a reduction in the operator's exposure to carcinogenic phenylenediamines.
Development of an enzyme-linked immunosorbent assay for the determination of the linear alkylbenzene sulfonates and long-chain sulfophenyl carboxylates using antibodies generated by pseudoheterologous immunization
Ramon-Azcon, Javier,Galve, Roger,Sanchez-Baeza, Francisco,Marco, M.-Pilar
, p. 71 - 81 (2008/02/12)
ELISA methods have been developed for screening contamination of water resources by linear alkyl benzene sulfonates (LAS) or the most immediate degradation products, the long chain sulfophenyl carboxylates, SPCs. The assay uses antibodies raised through pseudoheterologous immunization strategies using an equimolar mixture of two immunogens (SFA-KLH and 13C13-SPC-KLH) prepared by coupling N-(4-alkylpnenyl)sulfonyl-3-aminopropanoic acid (SFA) andp-(1-carboxy-13-tridecyl)-phenylsulfonic acid (13C13-SPC) to keyhole limpet hemocyanin (KLH). The immunizing haptens have been designed to address recognition versus two different epitopes of the molecule. The SFA hapten maximizes recognition of the alkyl moiety while preserving the complexity of the different alkyl chains present in the LAS technical mixture. The 13C13-SPC hapten addresses recognition of the common and highly antigenic phenylsulfonic group. The antisera raised using this strategy have been shown to be superior to those obtained through homologous immunization procedures using a single substance. By using an indirect ELISA format, LAS and long-chain SPCs can be detected down to 1.8 and 0.2 μg L-1, respectively. Coefficients of variation of 6 and 12% within and between assays, respectively, demonstrate immunoassay reproducibility. The assay can be used in media with a wide range of pH and ionic strength values. Preliminary experiments performed to assess matrix effects have demonstrated the potential applicability of the method as a screening tool to assess contamination by these types of surfactants in natural water samples.
Synthesis of cyclobutanones and four-membered enol ethers by using a rearrangement reaction of enol triflates
Tanino, Keiji,Aoyagi, Kotaro,Kirihara, Yasuhiro,Ito, Yoshikazu,Miyashita, Masaaki
, p. 1169 - 1172 (2007/10/03)
A new synthetic method of cyclobutanone derivatives and four-membered enol ethers via an intramolecular cyclization of a ketone enolate was developed. The cyclization precursors, enol triflates having a silyloxy group at the β′-position, were synthesized from the corresponding β-hydroxy ketones, which were prepared via an aldol reaction of a cycloalkanone and an aldehyde. Under the influence of TBAF, the enol triflates afforded a cyclobutanone or a four-membered enol ether through rearrangement of the trifluoromethanesulfonyl group followed by an intramolecular C- or O-alkylation reaction.
Cp2ZrCl2-mediated three-component coupling reactions of CO2, ethylene (or alkynes), and electrophiles leading to carboxylic acid derivatives
Yamashita, Kohei,Chatani, Naoto
, p. 919 - 922 (2007/10/03)
Zirconacycles 1 and 2 can be simply generated from Cp2ZrCl 2, EtMgBr, and an atmospheric pressure of CO2. The treatment of Cp2ZrCl2 with EtMgBr followed by exposure to CO2 generates zirconacycle 1, which can react with various electrophiles to give a variety of carboxylic acid derivatives. Unsaturated zirconacycles 2 can also generated from Cp2ZrCl2, EtMgBr, alkynes, and CO2. Complexes 2 react with electrophiles to give α,β-unsaturated acids stereoselectively.
Nitroxyl radical reactions with 4-pentenyl- and cyclopropylketenes: New routes to 5-hexenyl- and cyclopropylmethyl radicals
Allen,Fenwick,Henry-Riyad,Tidwell
, p. 5759 - 5765 (2007/10/03)
4-Pentenylketenes 4a and 9 and cyclopropylketenes 3a, 13, 14 (RCH=C=O) are generated by photochemical Wolff rearrangements and observed by IR as relatively long-lived species at room temperature in hydrocarbon solvents. The reactions of these ketenes with the nitroxyl radicals tetramethylpiperidinyloxyl (TEMPO, TO?) and tetramethylisoindoline-2-oxyl (TMIO, IO?) form carboxy substituted 5-hexenyl and cyclopropylmethyl radicals which are either trapped by a second nitroxyl radical or undergo rearrangements followed by trapping. The rate constant of the reaction of 4a with TEMPO was similar to that of n-BuCH=C=O (1b), while 3a was 4.3 times more reactive, indicating cyclopropyl stabilization of the incipient radical.
