3526-45-2Relevant academic research and scientific papers
A Facile Reduction Procedure for N,N′-bis[5-Substituted Salicylidene]-m/p-phenylenediamines with Sodium Borohydride-Silica Gel System
Sridharan,Muthusubramanian,Sivasubramanian
, p. 1087 - 1096 (2004)
An easy approach involving sodium borohydride/silica gel system offers a fast method of reduction for N,N′-bis[5-substituted salicylidene] m/p-phenylenediamines to the corresponding amines with excellent yield. The observed formation of boron chelates in
Highly selective and sensitive simultaneous nanomolar detection of Cs(i) and Al(iii) ions using tripodal organic nanoparticles in aqueous media: The effect of the urea backbone on chemosensing
Ganguli, Ashok K.,Kaur, Manpreet,Kaur, Navneet,Mishra, Jayanti
, p. 22691 - 22700 (2020)
Chemosensing plays a very important role in the detection of essential/pollutant ions in aqueous media. In this manuscript, two tripodal ligands, i.e., 1-(2-hydroxybenzyl)-3-(4-nitrophenyl)-1-phenylurea (ligand 1) and 1-(2-hydroxybenzyl)-3-(4-nitrophenyl)
Monitoring of reduction reaction of 2-((phenylimino)methyl)phenol compound with sodium borohydride in solution by infrared spectroscopy
Turhan, Onur,Ya?ar, Hatice
, (2020)
In this study, an imine compound 2-((phenylimino)methyl)phenol was synthesized by the reaction of salicylaldehyde and aniline for in situ monitoring of reduction with sodium borohydride. The reduction of C = N double bond to C–N in solution was continuous
Chiral N-heterocyclic carbene-iridium complexes for asymmetric reduction of prochiral ketimines
Kathuria, Lakshay,Samuelson, Ashoka G.
supporting information, (2020/12/28)
Enantioselective reduction of imines to the corresponding chiral secondary amines has been studied using a series of chiral half-sandwich iridium complexes. Chiral N-heterocyclic carbene (NHC) ligands in these complexes were synthesized from readily available, naturally occurring amino acids. Inexpensive phenylsilane was used as a convenient hydrogen donor. Under the optimized conditions, Ir-NHC complexes could reduce ketimines in good yields, albeit with moderate enantiomeric excess (ee). The phenylglycine derived chiral NHC was shown to give the best Ir catalyst and it also gave the maximum ee compared to catalysts prepared from other NHCs in this series. The opposite enantiomer of the reduction product was always obtained while using the Ir complex bearing a valine based NHC. The yields were consistently high with a variety of imine substrates having different steric and electronic demands.
Sulfated polyborate: A dual catalyst for the reductive amination of aldehydes and ketones by NaBH4
Ganwir, Prerna,Chaturbhuj, Ganesh
supporting information, (2021/05/19)
An efficient, quick, and environment-friendly one-pot reductive amination of aldehydes or ketones was developed. In ethanol at 70 °C, a imination catalyzed by sulfated polyborate and further reduced by sodium borohydride yields various amines. The present method has many significant benefits, including a shorter reaction time, excellent yields, and a hassle-free, straightforward experimental process. The reaction has a wide range of applications due to its flexibility, including secondary amine for reductive amination.
BF3·Et2O as a metal-free catalyst for direct reductive amination of aldehydes with amines using formic acid as a reductant
Fan, Qing-Hua,Liu, Xintong,Luo, Zhenli,Pan, Yixiao,Xu, Lijin,Yang, Ji,Yao, Zhen,Zhang, Xin
supporting information, p. 5205 - 5211 (2021/07/29)
A versatile metal- and base-free direct reductive amination of aldehydes with amines using formic acid as a reductant under the catalysis of inexpensive BF3·Et2O has been developed. A wide range of primary and secondary amines and diversely substituted aldehydes are compatible with this transformation, allowing facile access to various secondary and tertiary amines in high yields with wide functional group tolerance. Moreover, the method is convenient for the late-stage functionalization of bioactive compounds and preparation of commercialized drug molecules and biologically relevant N-heterocycles. The procedure has the advantages of simple operation and workup and easy scale-up, and does not require dry conditions, an inert atmosphere or a water scavenger. Mechanistic studies reveal the involvement of imine activation by BF3and hydride transfer from formic acid.
Screening of simple carbohydrates as a renewable organocatalyst for the efficient construction of 1,3-benzoxazine scaffold
Y?ld?r?m, Ayhan,Kaya, Yunus,G?ker, Mustafa
, (2021/10/12)
A convenient protocol for the two component preparation of 1,3-benzoxazines by using several protected and unprotected carbohydrate molecules as organocatalysts have been developed which is broadly applicable to condensation reaction between variety of Ma
Ruthenium N-Heterocyclic Carbene Complexes for Chemoselective Reduction of Imines and Reductive Amination of Aldehydes and Ketones
Kathuria, Lakshay,Samuelson, Ashoka G.
, (2020/06/17)
Chemoselective reduction of imines to secondary amines is catalyzed efficiently by tethered and untethered, half-sandwich ruthenium N-heterocyclic carbene (NHC) complexes at room temperature. The untethered Ru-NHC complexes are more efficient as catalysts for the reduction of aldimines and ketimines than the tethered complexes. Using the best untethered complex as a catalyst, electronic and steric demands on the reaction was probed using a series of imines. Chemoselectivity of the catalyst towards imine reduction was tested by performing inter and intramolecular competitive reactions in a variety of ways. The catalyst exhibits a very high TON and TOF under anaerobic conditions.
Reduction of imines catalysed by NHC substituted group 6 metal carbonyls
Reshi, Noor U Din,Kathuria, Lakshay,Samuelson, Ashoka G.
, p. 119 - 128 (2018/11/03)
The catalytic activity of a series of metal carbonyls [M(CO)6], and the corresponding NHC substituted [M(CO)5(NHC)], (M = Cr, Mo, W) complexes was examined in the reduction of N-benzylideneaniline and acetophenone using silyl hydrides and isopropanol/KOH as reductants. The use of various additives and ultraviolet irradiation to promote the reduction of imines using silyl hydrides as reductants was explored. From a comparison of the reactivity of [Mo(CO)6], [Mo(CO)5(NHC)], and [Mo(CO)4(bis NHC)] it was inferred that electron density on the metal centre plays a key role in the catalysis. Four of the best catalysts were then tested in the reduction of a variety of imines with different electronic and steric properties.
Multistep solid-state organic synthesis of carbamate-linked covalent organic frameworks
Lyle, Steven J.,Osborn Popp, Thomas M.,Waller, Peter J.,Pei, Xiaokun,Reimer, Jeffrey A.,Yaghi, Omar M.
supporting information, p. 11253 - 11258 (2019/08/07)
Herein, we demonstrate the first example of a multistep solid-state organic synthesis, in which a new imine-linked two-dimensional covalent organic framework (COF-170, 1) was transformed through three consecutive postsynthetic modifications into porous, crystalline cyclic carbamate and thiocarbamate-linked frameworks. These linkages are previously unreported and inaccessible through de novo synthesis. While not altering the overall connectivity of the framework, these chemical transformations induce significant conformational and structural changes at each step, highlighting the key importance of noncovalent interactions and conformational flexibility to COF crystallinity and porosity. These transformations were assessed using 15N multiCP-MAS NMR spectroscopy, providing the first quantitation of yields in COF postsynthetic modification reactions, as well as of amine defect sites in imine-linked COFs. This multistep COF linkage postsynthetic modification represents a significant step toward bringing the precision of organic solution-phase synthesis to extended solid-state compounds.
