55096-92-9Relevant articles and documents
Understanding water mediated proton migration in conversion of π-bond in olefinic carbon atoms into C–N bond to form β-amino adducts
Rathod, Prakash B.,Kumar, K.S. Ajish,Athawale, Anjali A.,Gopakumar, Gopinadhanpillai,Rao, C.V.S. Brahmmananda,Pandey, Ashok K.
, (2021/10/14)
The aza-Michael reactions with a variety of substrates were conducted in water affording the quantitative yields without any external catalyst, which is contrary to that published in literature. A more rational approach to analyze this problem was by conducting this conspicuous reaction with a variety of substrates in water and the results were analyzed using advanced theoretical calculations. Our investigation on the role of water in the reaction proposed a mechanism wherein water plays dual role both as medium as well as catalyst to facilitate the C–N bond formation using powerful tool in its armory, the “H-bonding”. Reactions were conducted in the absence of an external catalyst or co-solvents and, hence, are a greener approach in organic synthesis. The reactions of 15 examples were conducted with a variety of substrates to afford the addition products in the range of 70–95% yield. Theoretical studies on the transition state analysis suggested that it was the assistance of water, through H-bonding, that facilitated the conjugate addition of amine and proton transfer from ammonium ion, which could happen through two equally possible pathways.
Bio-heterogeneous Cu(0)NC@PHA for n-aryl/alkylation at room temperature
Jian Fui, Choong,Lutfor Rahman, Md,Musta, Baba,Sani Sarjadi, Mohd,Sarkar, Shaheen M.,Xin Ting, Tang
, (2021/06/28)
A pure cellulose was derived from waste fibre and it was chemically modified to a hydroxamic acid ligand. The poly(hydroxamic acid) was treated with an aqueous copper solution to afford the greenish stable five-membered copper complex; namely Cu(II)@PHA. Further, the Cu(II)@PHA was treated with a reducing agent hydrazine hydride to give brown colour cellulose supported copper nanocomplex (Cu(0)NC@PHA). The Cu(0)NC@PHA was characterised by ATR-FTIR, FE-SEM & EDS, TEM, ICP-OES, TGA, XRD and XPS analyses. The cellulose-based Cu(0)NC@PHA was used for the n-aryl/alkylation (Michael addition) reaction with a variety of α,β-unsaturated Michael acceptors to produce the corresponding n-aryl/alkyl products with an excellent yield at room temperature. The Cu(0)NC@PHA showed extraordinary stability and it was easily filtered out from the reaction mixture and may potentially recycled up to five times without loss of its original catalytic ability.
Late Stage Functionalization of Secondary Amines via a Cobalt-Catalyzed Electrophilic Amination of Organozinc Reagents
Gra?l, Simon,Chen, Yi-Hung,Hamze, Clémence,Tüllmann, Carl Phillip,Knochel, Paul
supporting information, p. 494 - 497 (2019/01/14)
A general preparation of polyfunctional hydroxylamine benzoates from the corresponding secondary amines is reported. This convenient synthesis allows the setup of a late-stage functionalization of various secondary amines, including pharmaceuticals and peptidic derivatives. Thus, a cross-coupling of hydroxylamine benzoates with various alkyl-, aryl-, and heteroaryl-zinc chlorides in the presence of 5 mol % CoCl2 (25 °C, 2 h) provides a range of polyfunctional tertiary amines. This method was used to prepare penfluridol and gepirone.
Tapioca cellulose based copper nanoparticles for chemoselective N-alkylation
Islam, Md. Shaharul,Mandal, Bablu Hira,Biswas, Tapan Kumar,Rahman, Md. Lutfor,Rashid,Tan, Suat-Hian,Sarkar, Shaheen M.
, p. 550 - 557 (2017/01/05)
Biomaterials as a support for catalysts are of prime importance. Tapioca root which is an abundant biopolymer source was used to synthesize cellulose supported bio-heterogeneous poly(hydroxamic acid) copper nanoparticles (CuN@PHA) and was characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma atomic emission spectroscopy (ICP-AES), transmission electron microscopy (TEM) analyses. The tapioca cellulose supported CuN@PHA (50 mol ppm) effectively catalyzed N-alkylation reaction of aliphatic amines with α,β-unsaturated compounds to give the corresponding alkylated products. High yields up to 95% were achieved for the converted products. The reusability of the cellulose supported nanoparticles was found to be excellent with no significant reduction of its catalytic activity over several cycles. The catalyst showed high catalytic activity having turnover number (TON) 18000 and turnover frequency (TOF) 2250 h-1.
Waste corn-cob cellulose supported bio-heterogeneous copper nanoparticles for aza-Michael reactions
Sarkar, Shaheen M.,Sultana,Biswas, Tapan Kumar,Rahman, Md. Lutfor,Yusoff, Mashitah Mohd
, p. 497 - 502 (2016/01/12)
Bio-heterogeneous poly(amidoxime) copper nanoparticles were prepared on the modified surface of waste corn-cob cellulose through a graft copolymerization process. The Cu-nanoparticles (0.05 mol% to 50 mol ppm) selectively promoted the aza-Michael reaction of aliphatic amines to give the corresponding alkylated products at room temperature in methanol. The supported nanoparticles were easy to recover and reused eight times without a significant loss of their activity.
Poly(hydroxamic acid) functionalized copper catalyzed C-N bond formation reactions
Islam, Md. Shaharul,Mandal, Bablu Hira,Biswas, Tapan Kumar,Rahman, Md. Lutfor,Rashid,Tan, Suat-Hian,Sarkar, Shaheen M.
, p. 56450 - 56457 (2016/07/06)
Highly active poly(hydroxamic acid) functionalized copper catalysts were synthesized by the surface modification of khaya cellulose through graft copolymerization and subsequent hydroximation processes. The prepared catalysts were well characterized by FTIR, FESEM, HRTEM, ICP-AES, UV-vis and XPS analyses. The supported catalysts effectively promoted C-N bond formation reactions and provided excellent yields of the corresponding products under mild reaction conditions. The catalysts were easy to recover from the reaction mixture and were reused several times without any significant loss of their catalytic activity.
Chemoselective catalytic conjugate addition of alcohols over amines
Uesugi, Shuhei,Li, Zhao,Yazaki, Ryo,Ohshima, Takashi
supporting information, p. 1611 - 1615 (2014/03/21)
A highly chemoselective conjugate addition of alcohols in the presence of amines is described. The cooperative nature of the catalyst enabled chemoselective activation of alcohols over amines, allowing the conjugate addition to soft Lewis basic α,β-unsaturated nitriles. Divergent transformation of the nitrile functionality highlights the utility of the present catalysis. The cooperative nature of a copper catalyst enabled the highly chemoselective activation of alcohols in the presence of amines and thus the conjugate addition of the hydroxy group to soft Lewis basic α,β-unsaturated nitriles. The presented method proceeds under proton-transfer conditions, reverses the innate reactivity of the OH and NH groups, and does not require protecting groups. dppe=1,2-bis(diphenylphosphino) ethane, MeSal=3-methylsalicylate. Copyright
An efficient biomaterial supported bifunctional organocatalyst (ES-SO 3- C5H5NH+) for the synthesis of β-amino carbonyls
Verma, Sanny,Jain, Suman L.,Sain, Bir
experimental part, p. 2314 - 2318 (2011/05/02)
A biomaterial supported organocatalyst, readily synthesized by the reaction of chemically modified sulfonic group containing expanded corn starch with pyridine exhibited excellent catalytic activity for the synthesis of β-amino carbonyls in excellent yields via aza-Michael addition of amines to electron deficient alkenes. A remarkable enhancement in the reaction rates was observed with the prepared bifunctional organocatalyst in comparison to the either starch grafted sulfonic acid or the corresponding homogeneous pyridinium p-toluenesulfonate.
Solvent-Dependent Reversible Rearrangement of 4-(Hydroxyimino)hexahydropyrimidines to 4-Aminotetrahydropyrimidine 3-Oxides
Korbonits, Dezsoe,Tobias-Heja, Erzsebet,Simon, Kalman,Kolonits, Pal
, p. 19 - 22 (2007/10/02)
1,2-Disubstituted 4-hydroxyiminohexahydropyrimidines (8) isomerize in alcohols to yield 1,2-disubstituted 4-aminotetrahydropyrimidine 3-oxides (9).In aprotic solvents the opposite transformation (9-->8) takes place, presumably by a different mechanism.The
