10017-11-5Relevant articles and documents
Transition metal-free catalytic reduction of primary amides using an abnormal NHC based potassium complex: Integrating nucleophilicity with Lewis acidic activation
Bhunia, Mrinal,Sahoo, Sumeet Ranjan,Das, Arpan,Ahmed, Jasimuddin,Sreejyothi,Mandal, Swadhin K.
, p. 1848 - 1854 (2020)
An abnormal N-heterocyclic carbene (aNHC) based potassium complex was used as a transition metal-free catalyst for reduction of primary amides to corresponding primary amines under ambient conditions. Only 2 mol% loading of the catalyst exhibits a broad substrate scope including aromatic, aliphatic and heterocyclic primary amides with excellent functional group tolerance. This method was applicable for reduction of chiral amides and utilized for the synthesis of pharmaceutically valuable precursors on a gram scale. During mechanistic investigation, several intermediates were isolated and characterized through spectroscopic techniques and one of the catalytic intermediates was characterized through single-crystal XRD. A well-defined catalyst and isolable intermediate along with several stoichiometric experiments, in situ NMR experiments and the DFT study helped us to sketch the mechanistic pathway for this reduction process unravelling the dual role of the catalyst involving nucleophilic activation by aNHC along with Lewis acidic activation by K ions.
Solvent-freeN-Boc deprotection byex situgeneration of hydrogen chloride gas
De Borggraeve, Wim M.,Gilles, Philippe,Van Mileghem, Seger,Verschueren, Rik H.
supporting information, p. 5782 - 5787 (2021/07/12)
An efficient, scalable and sustainable method for the quantitative deprotection of thetert-butyl carbamate (N-Boc) protecting group is described, using down to near-stoichiometric amounts of hydrogen chloride gas in solvent-free conditions. We demonstrate theex situgeneration of hydrogen chloride gas from sodium chloride and sulfuric acid in a two-chamber reactor, introducing a straightforward method for controlled and stoichiometric release of HCl gas. The solvent-free conditions allow deprotection of a wide variety ofN-Boc derivatives to obtain the hydrochloride salts in quantitative yields. The procedure obviates the need for any work-up or purification steps providing an uncomplicated green alternative to standard methods. Due to the solvent-free, anhydrous conditions, this method shows high tolerance towards acid sensitive functional groups and furnishes expanded functional group orthogonality.
Crosslinked Polymers
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, (2011/07/08)
Disclosed herein are pharmaceutical compositions comprising wet granulated bile acid sequestrants having the general Formula I shown, and their process of preparation. The present invention also discloses process for preparation of Colesevelam hydrochloride, an antilipemic agent.
A convenient method for the preparation of primary amines using tritylamine
Theodorou, Vassiliki,Ragoussis, Valentine,Strongilos, Alexandros,Zelepos, Evangelos,Eleftheriou, Argyro,Dimitriou, Maria
, p. 1357 - 1360 (2007/10/03)
A simple method for the preparation of primary amines by treating N-tritylamines with trifluoroacetic acid has been established. The N-tritylamines were prepared by the reaction of alkyl halides or alkyl p-toluenesulfonates with tritylamine, or by the reaction of alkyl bromides with lithium tritylamide.
Method for treating hypercholesterolemia with polyallylamine polymers
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, (2008/06/13)
A method for removing bile salts from a patient that includes administering to the patient a therapeutically effective amount of a non-absorbable amine polymer characterized by a repeat unit having the formula: and salts thereof, where n is a positive integer and x is zero or an integer between 1 and about 4.
Method for reducing oxalate
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, (2008/06/13)
A method for reducing oxalate levels in a patient that includes administering to the patient a therapeutically effective amount of non-absorbable amine polymers such as a polymer characterized by a repeat unit having the formula: STR1 and salts and copolymers thereof, where n is a positive integer and x is zero or an integer between 1 and about 4.
Amine polymer sequestrant and method of cholesterol depletion
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, (2008/06/13)
An amine polymer includes first and second substituents bound to amines of the polymer. The first substituent includes a hydrophobic moiety. The second substituent includes a quaternary amine-containing moiety. A method for binding bile salts of bile acids in a mammal includes orally administering to the mammal a therapeutically-effective amount of the amine polymer.
Hydrophobic amine polymer sequestrant and method of cholesterol depletion
-
, (2008/06/13)
An amine polymer includes a substituent bound to an amine of the polymer. The substituent includes a quaternary amine-containing moiety having at least one hydrophobic moiety. A method for binding bile salts of bile acids in a mammal includes orally administering to the mammal a therapeutically-effective amount of the amine polymer.
Method for removing bile salts from a patient with alkylated amine polymers
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, (2008/06/13)
A method for removing bile salts from a patient that includes administering to the patient a therapeutically effective amount of product produced by a process comprising alkylating one or more crosslinked amine polymers, salts or copolymers thereof with at least one alkylating agent. The reaction product is characterized in that: (i) at least some of the nitrogen atoms are unreacted with alkylating agent; and (ii) less than 10 mol% of the nitrogen atoms in the polymer react with the alkylating agent to form quaternary ammonium units.
Phosphate-binding polymers for oral administration
-
, (2008/06/13)
Phosphate-binding polymers are provided for removing phosphate from the gastrointestinal tract. The polymers are orally administered, and are useful for the treatment of hyperphosphatemia.
