942-05-2Relevant articles and documents
Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
Pandey, Pragati,Bera, Jitendra K.
, p. 9204 - 9207 (2021/09/20)
A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
Lithium compound catalyzed deoxygenative hydroboration of primary, secondary and tertiary amides
Bisai, Milan Kumar,Gour, Kritika,Das, Tamal,Vanka, Kumar,Sen, Sakya S.
supporting information, p. 2354 - 2358 (2021/03/03)
A selective and efficient route for the deoxygenative reduction of primary to tertiary amides to corresponding amines has been achieved with pinacolborane (HBpin) using simple and readily accessible 2,6-di-tert-butyl phenolate lithium·THF (1a) as a catalyst. Both experimental and DFT studies provide mechanistic insight. This journal is
Phosphine-Free Manganese Catalyst Enables Selective Transfer Hydrogenation of Nitriles to Primary and Secondary Amines Using Ammonia-Borane
Sarkar, Koushik,Das, Kuhali,Kundu, Abhishek,Adhikari, Debashis,Maji, Biplab
, p. 2786 - 2794 (2021/03/03)
Herein we report the synthesis of primary and secondary amines by nitrile hydrogenation, employing a borrowing hydrogenation strategy. A class of phosphine-free manganese(I) complexes bearing sulfur side arms catalyzed the reaction under mild reaction conditions, where ammonia-borane is used as the source of hydrogen. The synthetic protocol is chemodivergent, as the final product is either primary or secondary amine, which can be controlled by changing the catalyst structure and the polarity of the reaction medium. The significant advantage of this method is that the protocol operates without externally added base or other additives as well as obviates the use of high-pressure dihydrogen gas required for other nitrile hydrogenation reactions. Utilizing this method, a wide variety of primary and symmetric and asymmetric secondary amines were synthesized in high yields. A mechanistic study involving kinetic experiments and high-level DFT computations revealed that both outer-sphere dehydrogenation and inner-sphere hydrogenation were predominantly operative in the catalytic cycle.
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 (2020/03/03)
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.
Boron-Catalyzed Silylative Reduction of Nitriles in Accessing Primary Amines and Imines
Gandhamsetty, Narasimhulu,Jeong, Jinseong,Park, Juhyeon,Park, Sehoon,Chang, Sukbok
, p. 7281 - 7287 (2015/07/28)
Silylative reduction of nitriles was studied under transition metal-free conditions by using B(C6F5)3 as a catalyst with hydrosilanes as a reductant. Alkyl and (hetero)aryl nitriles were efficiently converted to primary amines or imines under mild conditions. The choice of silanes was found to determine the selectivity: while a full reduction of nitriles was highly facile, the use of sterically bulky silanes allowed for the partial reduction leading to N-silylimines.
A practical procedure for reduction of primary, secondary and tertiary amides to amines
Reeves, Jonathan T.,Tan, Zhulin,Marsini, Maurice A.,Han, Zhengxu S.,Xu, Yibo,Reeves, Diana C.,Lee, Heewon,Lu, Bruce Z.,Senanayake, Chris H.
supporting information, p. 47 - 52 (2013/03/13)
A mild and general procedure for reduction of primary, secondary, and tertiary amides using catalytic triruthenium dodecacarbonyl and 1,1,3,3-tetramethyldisiloxane as reductant is described. The reaction is tolerant of numerous functional groups, and the amine products can often be isolated by direct crystallization as hydrochloride salts. The catalyst and silane are commercially available, air stable, and inexpensive, making the procedure accessible for both laboratory and large-scale applications. Copyright
Hydrosiloxane-Ti(OiPr)4: An efficient system for the reduction of primary amides into primary amines as their hydrochloride salts
Laval, Stéphane,Dayoub, Wissam,Pehlivan, Leyla,Métay, Estelle,Favre-Réguillon, Alain,Delbrayelle, Dominique,Mignani, Gérard,Lemaire, Marc
experimental part, p. 4072 - 4075 (2011/09/12)
A simple and useful method for the reduction of primary amides into the corresponding amines using a polymethylhydrosiloxane (PMHS)-Ti(OiPr)4 reducing system is described. Aromatic as well as aliphatic primary amides are reduced in high selectivity and excellent yields. The reduction could proceed via dehydration of the primary amide group into the corresponding nitrile which is then reduced into the corresponding primary amine.
Process for the preparation of β-cyclo-substituted ethylamines
-
, (2008/06/13)
The present invention provides a multistep process for the preparation of β-cyclo-substituted ethylamines of the general formula:- in which AR is a heterocyclic or non-heterocyclic aromatic radical, which is optionally mono- or poly- substituted, wherein said compounds represent a class of intermediates which can be converted to 4,5,6,7-tetrahydro[3,2-C] or [2,3-C]pyridines wherein the latter are useful for anti-inflammatory, vasodilator or blood platelet aggregation inhibition activities.
