936-26-5Relevant academic research and scientific papers
Cu-Catalyzed Site-Selective Benzylic Chlorination Enabling Net C–H Coupling with Oxidatively Sensitive Nucleophiles
Lopez, Marco A.,Buss, Joshua A.,Stahl, Shannon S.
supporting information, p. 597 - 601 (2022/01/20)
Site-selective chlorination of benzylic C–H bonds is achieved using a CuICl/bis(oxazoline) catalyst with N-fluorobenzenesulfonimide as the oxidant and KCl as a chloride source. This method exhibits higher benzylic selectivity, relative to estab
Iron-catalysed enantioconvergent Suzuki-Miyaura cross-coupling to afford enantioenriched 1,1-diarylalkanes
Tyrol, Chet C.,Yone, Nang S.,Gallin, Connor F.,Byers, Jeffery A.
supporting information, p. 14661 - 14664 (2020/12/02)
The first stereoconvergent Suzuki-Miyaura cross-coupling reaction was developed to afford enantioenriched 1,1-diarylalkanes. An iron-based complex containing a chiral cyanobis(oxazoline) ligand framework was best to obtain enantioenriched 1,1-diarylalkanes from cross-coupling reactions between unactivated aryl boronic esters and benzylic chlorides. Enhanced yields were obtained when 1,3,5-trimethoxybenzene was used as an additive, which is hypothesized to extend the lifetime of the iron-based catalyst. Exceptional enantioselectivities were obtained with challenging ortho-substituted benzylic chlorides. This journal is
Synthesis and evaluation of potent and selective MGL inhibitors as a glaucoma treatment
Alapafuja, Shakiru O.,Malamas, Michael S.,Shukla, Vidyanand,Zvonok, Alexander,Miller, Sally,Daily, Laura,Rajarshi, Girija,Miyabe, Christina Yume,Chandrashekhar, Honrao,Wood, JodiAnne,Tyukhtenko, Sergiy,Straiker, Alex,Makriyannis, Alexandros
, p. 55 - 64 (2018/11/23)
Monoacylglycerol lipase (MGL) inhibition provides a potential treatment approach to glaucoma through the regulation of ocular 2-arachidonoylglycerol (2-AG) levels and the activation of CB1 receptors. Herein, we report the discovery of new series of carbamates as highly potent and selective MGL inhibitors. The new inhibitors showed potent nanomolar inhibitory activity against recombinant human and purified rat MGL, were selective (>1000-fold) against serine hydrolases FAAH and ABHD6 and lacked any affinity for the cannabinoid receptors CB1 and CB2. Protein-based 1H NMR experiments indicated that inhibitor 2 rapidly formed a covalent adduct with MGL with a residence time of about 6 h. This interconversion process “intrinsic reversibility” was exploited by modifications of the ligand's size (length and bulkiness) to generate analogs with “tunable’ adduct residence time (τ). Inhibitor 2 was evaluated in a normotensive murine model for assessing intraocular pressure (IOP), which could lead to glaucoma, a major cause of blindness. Inhibitor 2 was found to decrease ocular pressure by ~4.5 mmHg in a sustained manner for at least 12 h after a single ocular application, underscoring the potential for topically-administered MGL inhibitors as a novel therapeutic target for the treatment of glaucoma.
Nucleophilic Substitutions of Alcohols in High Levels of Catalytic Efficiency
Stach, Tanja,Dr?ger, Julia,Huy, Peter H.
supporting information, p. 2980 - 2983 (2018/05/28)
A practical method for the nucleophilic substitution (SN) of alcohols furnishing alkyl chlorides, bromides, and iodides under stereochemical inversion in high catalytic efficacy is introduced. The fusion of diethylcyclopropenone as a simple Lewis base organocatalyst and benzoyl chloride as a reagent allows notable turnover numbers up to 100. Moreover, the use of plain acetyl chloride as a stoichiometric promotor in an invertive SN-type transformation is demonstrated for the first time. The operationally straightforward protocol exhibits high levels of stereoselectivity and scalability and tolerates a variety of functional groups.
A General Catalytic Method for Highly Cost- and Atom-Efficient Nucleophilic Substitutions
Huy, Peter H.,Filbrich, Isabel
supporting information, p. 7410 - 7416 (2018/04/30)
A general formamide-catalyzed protocol for the efficient transformation of alcohols into alkyl chlorides, which is promoted by substoichiometric amounts (down to 34 mol %) of inexpensive trichlorotriazine (TCT), is introduced. This is the first example of a TCT-mediated dihydroxychlorination of an OH-containing substrate (e.g., alcohols and carboxylic acids) in which all three chlorine atoms of TCT are transferred to the starting material. The consequently enhanced atom economy facilitates a significantly improved waste balance (E-factors down to 4), cost efficiency, and scalability (>50 g). Furthermore, the current procedure is distinguished by high levels of functional-group compatibility and stereoselectivity, as only weakly acidic cyanuric acid is released as exclusive byproduct. Finally, a one-pot protocol for the preparation of amines, azides, ethers, and sulfides enabled the synthesis of the drug rivastigmine with twofold SN2 inversion, which demonstrates the high practical value of the presented method.
Manganese-salen catalyzed oxidative benzylic chlorination
Sasmal, Sheuli,Rana, Sujoy,Lahiri, Goutam Kumar,Maiti, Debabrata
, (2018/07/14)
Abstract: Metalloporphyrins are well-known to serve as the model for mimicking reactivities exhibited by cytochrome P450 hydroxylase. Recent developments on selective C–H halogenation using Mn-porphyrins provided the way for understanding the reactivity as well as mechanism of different halogenase enzymes. In this report, we demonstrated a method for benzylic C–H chlorination using easily prepared Mn(salen) complex as the catalyst, which shows a complementary reactivity of Mn-porphyrins. Here, NaOCl has been used as a chlorinating source as well as the oxidant. Efforts towards understanding the mechanism suggested the formation of the high-valent Mn(V)=O species which is believed to be the key intermediate to conduct this transformation. Graphical abstract: SYNOPSIS Mn(salen)-catalyzed selective benzylic chlorination protocol has been developed using aqueous NaOCl solution. Reactions proceeded efficiently at room temperature and displayed good functional group tolerance. The mechanistic investigation demonstrated that Mn (V) = O species is likely to be the key intermediate which is responsible to generate benzylic radical. EPR and ESI-MS studies confirmed the in situ formation of Mn(IV)-species.[Figure not available: see fulltext.].
UREA/CARBAMATES FAAH MAGL OR DUAL FAAH/MAGL INHIBITORS AND USES THEREOF
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Paragraph 0127, (2016/02/18)
Disclosed are compounds that may be used to inhibit the action of fatty acid amide hydrolase (FAAH), monoacylglycerol lipase (MAGL) or dual FAAH/MAGL.
METHOD OF CONVERTING ALCOHOL TO HALIDE
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Page/Page column 51; 114; 121, (2017/01/02)
The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.
THE REACTION OF BENZYLIC ALCOHOLS WITH CHLOROTRIMETHYLSILANE/DIMETHYL SULPHOXIDE
Bellesia, Franco,Ghelfi, Franco,Pagnoni, Ugo Maria,Pinetti, Adriano
, p. 437 - 439 (2007/10/02)
With catalytic amounts of chlorotrimethylsilane/dimethyl sulphoxide (CTMSO/DMSO) in acetonitrile benzylic alcohols have been found to give high yields of styrenes.By using stoicheiometric amounts of reagents, different reaction pathways are observed: an elimination-addition sequence occurs with secondary and tertiary alcohols affording vicinal dichloro derivatives, β-chloro thioethers and allyl chlorides, whereas a nucleophilic substitution to the corresponding monochlorides occurs starting from primary and sterically hindered substrates.
Mechanical Activation of Magnesium Turnings for the Preparation of Reactive Grignard Reagents
Baker, Karen V.,Brown, John M.,Hughes, Nigel,Skarnulis, A. Jerome,Sexton, Ann
, p. 698 - 703 (2007/10/02)
Preactivation of magnesium by dry stirring in an inert atmosphere is highly beneficial for the clean synthesis of reactive allylic or benzylic organomagnesium chlorides.This procedure routinely produces 0.4 M solutions of the Grignard reagent in diethyl ether free from coupling products.The purity may be directly assayed by 13C spectroscopy.Using spin saturation transfer techniques, the rate constant for interconversion of the enantiomers of (1-phenyl-2-methylpropyl)magnesium chloride in Et2O at 25 deg C was shown to be -1.Electron microscopy has been used to define the surface changes occurring during the dry stirring of magnesium turnings.
