1693-39-6Relevant academic research and scientific papers
Ruthenium Removal Using Silica-Supported Aromatic Isocyanides
Gregg, Zackary R.,Glickert, Elise,Xu, Ruoshui,Diver, Steven T.
, (2021)
New silica gel scavengers containing aromatic isocyanides have been synthesized and evaluated for Ru removal. A thiol-ene click reaction was used to attach the isocyanide precursor to a thiol-containing siloxane. Conventional methods for grafting to silica gel at elevated temperature resulted in significant hydrolysis of the isocyanide. A novel cleavage reaction was developed to quantitate the amount of surface-loaded isocyanide. Binding by the new materials was comparatively evaluated for a variety or Ru carbene catalysts. The optimal conditions were extended to two ring-closing metatheses (RCM). The residual Ru was determined by inductively coupled plasma mass spectrometry (ICP-MS). For facile RCM reactions, the UV data agreed with the ICP-MS results. However, more difficult RCM did not correlate well with the UV data. This was interpreted in terms of varying extent of catalyst decomposition. In all cases, isocyanide scavenger reagents were found to be superior to commonly used, silica gel-based metal scavengers.
DMF·HCl as a versatile and straightforward N- and O-formylating agent
Ramírez-Vázquez, Dulce G.,Vi?as-Bravo, Omar,Martínez-Pascual, Roxana,Pérez-Picaso, Lemuel,Castro-Cerritos, Karla Viridiana
supporting information, p. 585 - 592 (2020/11/19)
Inspired by the serendipitous isolation of N-formylpiperazines when we attempted the synthesis of a series of piperazines, we have developed a straightforward methodology for the N- and O- formylation of secondary cyclic amines, anilines and steroids, respectively. Such approach is based on the hitherto non-reported use of DMF·HCl complex, as a versatile and easily-available formylating system that can be stored without apparent loss of activity.
Reductive Formylation of Nitroarenes using HCOOH over Bimetallic C?N Framework Derived from the Integration of MOF and COF
Kumar Kar, Ashish,Srivastava, Rajendra
, p. 3174 - 3183 (2021/05/27)
CoZn embedded C?N framework is prepared by the carbonization of CoZn containing MOF integrated with COF porous architecture in Ar atmosphere. The graphitic nature of porous carbon is confirmed from Raman analysis. The porosity and nanostructure information are retrieved from N2-sorption and transmission electron microscopic analysis, respectively. The incorporation of different metals and their oxidation states and types of nitrogen present in the C?N framework are confirmed from X-ray photoelectron spectroscopy. The basicity of the materials is determined from a CO2-temperature programmed desorption. ZnCo embedded C?N framework exhibits excellent activity in the selective reductive formylation using HCOOH. For comparison, more than 15 materials are prepared, and their activities are compared. Several control experiments are performed to establish a structure-activity relation. The recycling experiment, hot-filtration test, and poisoning experiment demonstrate the metal embedded porous C?N framework‘s recyclability and stability. A reaction mechanism for the reductive N-formylation of nitroaromatics is presented based on structure-activity relationship, control reactions, and physicochemical characterizations. The development of interesting MOF-COF-derived metal nanoclusters embedded C?N framework for selective reductive formylation of nitroaromatics using formic acid will be highly attractive to catalysis researchers and industrialists.
HCl-mediated transamidation of unactivated formamides using aromatic amines in aqueous media
Dhawan, Sanjeev,Girase, Pankaj Sanjay,Kumar, Vishal,Karpoormath, Rajshekhar
, p. 3729 - 3739 (2021/10/14)
We report transamidation protocol to synthesize a range of secondary and tertiary amides from weakly nucleophilic aromatic and hetero-aryl amines with low reactive formamide derivatives, utilizing hydrochloric acid as catalyst. This current acid mediated strategy is beneficial because it eliminates the need for a metal catalyst, promoter or additives in the reaction, simplifies isolation and purification. Notably, this approach conventionally used to synthesize molecules on gram scales with excellent yields and a high tolerance for functional groups.
Catalyst freeN-formylation of aromatic and aliphatic amines exploiting reductive formylation of CO2using NaBH4
Kumar, Arun,Kumar, Yashwant,Mahajan, Dinesh,Sharma, Nidhi,Sharma, Pankaj
, p. 25777 - 25787 (2021/08/05)
Herein, we report a sustainable approach forN-formylation of aromatic as well as aliphatic amines using sodium borohydride and carbon dioxide gas. The developed approach is catalyst free, and does not need pressure or a specialized reaction assembly. The reductive formylation of CO2with sodium borohydride generates formoxy borohydride speciesin situ, as confirmed by1H and11B NMR spectroscopy. Thein situformation of formoxy borohydride species is prominent in formamide based solvents and is critical for the success of theN-formylation reactions. The formoxy borohydride is also found to promote transamidation reactions as a competitive pathway along with reductive functionalization of CO2with amine leading toN-formylation of amines.
Palladium supported on MRGO@CoAl-LDH catalyzed reductive carbonylation of nitroarenes and carbonylative Suzuki coupling reactions using formic acid as liquid CO and H2 source
Jadidi Nejad, Masoumeh,Heydari, Akbar
, (2021/07/17)
In the present study, a heterogeneous palladium catalyst system, Pd nanoparticles supported on MRGO@CoAl-LDH, was synthesized and employed in reductive carbonylation of nitroarenes and carbonylative Suzuki coupling reactions using formic acid as CO and H2 source. The as-obtained heterogeneous catalyst was characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The nanocatalyst was reused for 5 cycles with a negligible reduction in the yield of products. All reactions were carried out with high yields and under suitable and safe conditions. Also, we have successfully applied formic acid as a good and safe alternative to CO and H2 gases.
Efficient: N -formylation of primary aromatic amines using novel solid acid magnetic nanocatalyst
Agarwal, Alka,Awasthi, Satish K.,Yadav, Jitendra Kumar,Yadav, Priyanka
, p. 41229 - 41236 (2020/11/23)
Sulfonic acid functionalized over biguanidine fabricated silica-coated heterogeneous magnetic nanoparticles (NP?SO3H) have been synthesized, well characterized and explored for the first time, as an efficient and recyclable catalyst for N-formylation of primary amines under mild reaction conditions. Exploiting the magnetic nature of Fe3O4, the prepared catalyst was readily recovered from the reaction mixture via an external magnet. The catalyst can be reused for up to six cycles without any substantial loss of catalytic activity. The cost effectiveness, simple methodology, wide substrate tolerance, excellent yield and easy work-up are the additional advantages of present catalytic system. This journal is
Application of Ag/TFPG-DMB COF in carbamates synthesis via CO2 fixation reaction and one-pot reductive N-formylation of nitroarenes under sunlight
Biswas, Surajit,Hazra Chowdhury, Arpita,Hazra Chowdhury, Ipsita,Islam, Sk. Manirul
, (2020/06/25)
We have designed mesoporous AgNPs decorated COF (Ag/TFPG-DMB COF) nanomaterial which has been formed by an easy ex-situ synthetic method. The synthesized material is characterized by FTIR, PXRD, UV–vis, N2 adsorption–desorption studies, TEM, FESEM and XPS. The material showed the generation of identical mesopore at 3.9 nm. It is observed that the material can perform as both thermally and photochemically active catalyst for carbamate synthesis and one-pot reduction and N-formylation of nitroarenes respectively. The catalytic activity of the Ag/ TFPG-DMB COF nanomaterial is checked for green synthesis of carbamates from different amines and alcohols under 1 atmospheric pressure of CO2 with excellent yield (upto 95 %) as well as with high TOF value (182 h?1) and high selectivity. Additionally, the Ag/ TFPG-DMB COF nanomaterial is also applied as a potentially active photocatalyst for one-pot nitroarene reduction along with N-formylation reaction under sunlight irradiation in green reaction conditions with exceptionally high yield of formylated products upto 99 % as well as with high TOF value (762 h ?1). The catalyst efficiently reduced and formylated para-nitrophenol, a potential water pollutant, which elaborates its scope as an efficient catalyst for water purification also. The catalyst recyclability is also checked for five reaction cycles for both the reactions and the Ag/TFPG-DMB COF material showed outstanding recycling ability without any noticeable leaching of active metal or catalyst degradation.
Effective and selective direct aminoformylation of nitroarenes utilizing palladium nanoparticles assisted by fibrous-structured silica nanospheres
Jaseer, E. A.,Qureshi, Ziyauddin S.
, (2020/07/09)
Abstract: Palladium nanoparticles (~ 1–3?nm, 0.4?wtpercent Pd) were uniformly distributed over the surface of fibrous silica nanospheres (KCC-1) modified via aminopropyltriethoxysilane using a fast and cost-effective palladium (II) chloride reduction process. The Pd nanoparticles (Pd NPs) distribution over the ensuing catalyst Pd/KCC-1-NH2 showed much more uniform distribution, and smaller size compared with the tedious hydrothermal reduction method. The morphological, chemical, and size analyses of Pd/KCC-1-NH2 by BET, UV–Vis spectra, XRD, HR-TEM, EDS and XPS analysis revealed that the succeeding material consist of a distinct fibrous silica nanospheres support adorn with Pd NPs. The resultant nanocatalyst was tested for the one-step reductive aminoformylation of aromatic nitro compounds using formic acid. A wide range of substituted nitroarenes including electron withdrawing, releasing, sterically hindered and multifunctional groups have been converted to corresponding aryl formamide in quantitative yields (yields up to 98percent) at moderate temperature (70?°C). Optimization study has proved that the 6 equivalent of formic acid is required and toluene was found to be the better solvent. The established practice is beneficial due to the use of formic acid as H2 source and formylating agent, easiness in handling of the catalyst and simple workup procedure with efficient catalyst reusability. Graphic abstract: [Figure not available: see fulltext.].
Mesostructure organic-inorganic hybrid ionic liquids based on heteropoly acids: Effect of linkage on the molecular structure and catalytic activity
Shahebrahimi, Shabnam,Rafiee, Ezzat,Sadrjavadi, Komail
, (2019/08/30)
The new inorganic–organic hybrids based on SO3H-functionalized ionic liquids (ILs) and Keggin-type heteropoly acids (H3PW12O40, H3PMo12O40, and H4SiW12O40; HPAs) are prepared and characterized by FT-IR, NMR, XRD, CV, SEM/EDX, ICP-OES, BJH and UV. Different molecular structures according to the different inorganic part were also proved. Potentiometric titration showed a good relationship between catalytic activity and acidity of the catalysts. Electrochemical aspects showed electron transfer ability of the compounds. For understanding catalytic activities of the HPA-IL hybrids in N-formylation reaction, effect of catalyst composition, substrate, and reaction conditions were studied. The best SO3H-functionalized ionic liquid catalyst was readily recovered and reused for four runs. Easy preparation of the catalyst, simple and easy work-up, mild reaction conditions, low cost, excellent yields and short reaction times are the key features of this work.
