15429-17-1Relevant academic research and scientific papers
Switching Selectivity in Copper-Catalyzed Transfer Hydrogenation of Nitriles to Primary Amine-Boranes and Secondary Amines under Mild Conditions
Song, Hao,Xiao, Yao,Zhang, Zhuohua,Xiong, Wanjin,Wang, Ren,Guo, Liangcheng,Zhou, Taigang
, p. 790 - 800 (2022/01/11)
A simple and efficient copper-catalyzed selective transfer hydrogenation of nitriles to primary amine-boranes and secondary amines with an oxazaborolidine-BH3 complex is reported. The selectivity control was achieved under mild conditions by switching the solvent and the copper catalysts. More than 30 primary amine-boranes and 40 secondary amines were synthesized via this strategy in high selectivity and yields of up to 95%. The strategy was applied to the synthesis of 15N labeled in 89% yield.
Nickel Complexes Bearing N,N,O-Tridentate Salicylaldiminato Ligand: Efficient Catalysts for Imines Formation via Dehydrogenative Coupling of Primary Alcohols with Amines
Han, Zhangang,Hao, Zhiqiang,Lin, Jin,Lu, Guo-Liang,Zhang, Junhua,Zhang, Xiaoying
, p. 3843 - 3853 (2021/11/18)
Treatment of salicylaldiminato ligand L1H-L2H (L1H = 2,4-di-tert-butyl-6-((quinolin-8-ylimino)methyl)phenol; L2H = 2,4-di-tert-butyl-6-(((2-(diethylamino)ethyl)imino)methyl)phenol) with Ni(OAc)2·4H2O in refluxing ethanol afforded nickel complexes [(L1)Ni(OAc)] (1) and [(L2)Ni(OAc)] (2), respectively. Reaction of L3H (L3H = (2,4-di-tert-butyl-6-(((2-(pyridin-2-yl)ethyl)imino)methyl)phenol)) with Ni(OAc)2·4H2O in the presence of excess triethylanmine gave the dual ligands coordinated nickel complex [(L2)2Ni] (3). Complexes 1-3 were well characterized by high-resolution mass spectrometry, infrared spectroscopy, elemental analysis, and X-ray diffraction analysis. All the three Ni(II) complexes exhibited efficient activity and good selectivity in the acceptorless dehydrogenative coupling of alcohols and amines to produce imines and diimines. The present protocol provides an atom-economical and sustainable route for the synthesis of various imine derivatives by employing an earth-abundant nickel salt and easily prepared salicylaldiminato ligands.
Expanding Water/Base Tolerant Frustrated Lewis Pair Chemistry to Alkylamines Enables Broad Scope Reductive Aminations
Fasano, Valerio,Ingleson, Michael J.
supporting information, p. 2217 - 2224 (2017/02/18)
Lower Lewis acidity boranes demonstrate greater tolerance to combinations of water/strong Br?nsted bases than B(C6F5)3, this enables Si?H bond activation by a frustrated Lewis pair (FLP) mechanism to proceed in the presence of H2O/alkylamines. Specifically, BPh3has improved water tolerance in the presence of alkylamines as the Br?nsted acidic adduct H2O–BPh3does not undergo irreversible deprotonation with aliphatic amines in contrast to H2O–B(C6F5)3. Therefore BPh3is a catalyst for the reductive amination of aldehydes and ketones with alkylamines using silanes as reductants. A range of amines inaccessible using B(C6F5)3as catalyst, were accessible by reductive amination catalysed by BPh3via an operationally simple methodology requiring no purification of BPh3or reagents/solvent. BPh3has a complementary reductive amination scope to B(C6F5)3with the former not an effective catalyst for the reductive amination of arylamines, while the latter is not an effective catalyst for the reductive amination of alkylamines. This disparity is due to the different pKavalues of the water–borane adducts and the greater susceptibility of BPh3species towards protodeboronation. An understanding of the deactivation processes occurring using B(C6F5)3and BPh3as reductive amination catalysts led to the identification of a third triarylborane, B(3,5-Cl2C6H3)3, that has a broader substrate scope being able to catalyse the reductive amination of both aryl and alkyl amines with carbonyls.
Ultrasound-assisted solventless synthesis of amines by in situ oxidation/reductive amination of benzyl halides
Khumraksa, Bannarak,Phakhodee, Wong,Pattarawarapan, Mookda
, p. 20454 - 20458 (2014/06/09)
Ultrasound-assisted solventless oxidation/reductive amination of benzyl halides was developed as a facile, efficient, and environmental friendly method toward N-alkylated amines. Aldehydes were formed in situ by oxidation of organic halides with N-methylmorpholine N-oxide (NMO), followed by direct reductive amination with amines using sodium borohydride and montmorillonite K-10 catalyst as the reducing system. This green and simple procedure enables N-alkylated amines to be prepared in good to excellent yields with high selectivity of the monoalkylation. This journal is the Partner Organisations 2014.
Iodine mediated deprotection of N-tert-butanesulfinyl amines: A functional group compatible method
Chen, Wen,Ren, Jian,Wang, Minshou,Dang, Lingjing,Shen, Xianfu,Yang, Xiaodong,Zhang, Hongbin
supporting information, p. 6259 - 6262 (2014/06/09)
In the presence of iodine, a functional group compatible method for the deprotection of tert-butanesulfinyl and p-toluenesulfinyl units was developed. This journal is the Partner Organisations 2014.
Zinc-catalyzed chemoselective reduction of tertiary and secondary amides to amines
Das, Shoubhik,Addis, Daniele,Junge, Kathrin,Beller, Matthias
experimental part, p. 12186 - 12192 (2011/11/07)
General and convenient procedures for the catalytic hydrosilylation of secondary and tertiary amides under mild conditions have been developed. In the presence of inexpensive zinc catalysts, tertiary amides are easily reduced by applying monosilanes. Key to success for the reduction of the secondary amides is the use of zinc triflate and disilanes with dual Si-H moieties. The presented hydrosilylations proceed with excellent chemoselectivity in the presence of sensitive ester, nitro, azo, nitrile, olefins, and other functional groups, thus making the method attractive for organic synthesis.
Ruthenium-catalyzed nitro and nitrile compounds coupling with alcohols: Alternative route for N-substituted amine synthesis
Cui, Xinjiang,Zhang, Yan,Shi, Feng,Deng, Youquan
supporting information; experimental part, p. 2587 - 2591 (2011/04/12)
The one-pot synthesis of N-substituted secondary amines from nitrobenzenes and benzonitriles has been developed (see scheme). This report presents a versatile and simple method for the synthesis of N-substituted amines in excellent yield and high efficiency from nitro and nitrile compounds with alcohols.
Reduction and reductive coupling of imines by Sm(II)-based reagents
Kim, Myeongseob,Knettle, Brian W.,Dahlén, Anders,Hilmersson, G?ran,Flowers II, Robert A.
, p. 10397 - 10402 (2007/10/03)
The reductive coupling of aldimines and ketimines by a series of Sm(II)-based reagents (SmI2, SmI2-HMPA, SmBr2, Sm{N[Si(CH3)3]2}2, and SmI 2/triethylamine/water) were examined. In general, aldimines and ketimines were efficiently reduced or coupled using reductants that are more powerful than SmI2, and the use of Sm{N[Si(CH3) 3]2}2 led to higher diastereoselectivities in reductive coupling reactions. Surprisingly, only the combination of SmI 2/triethylamine/water was capable of reducing and coupling para-substituted benzaldimines and coupling ketimines.
EFFECTS OF SUBSTITUENTS IN THE BENZYL BROMIDE ON THE KINETICS OF THE BENZYLATION OF AMINES
Shpan'ko, I. V.,Korostylev, A. P.,Rusu, L. N.
, p. 1715 - 1723 (2007/10/02)
The kinetics of the reactions of 3- and 4-substituted benzyl bromides with amines having various structures in nitrobenzene at 40 deg C were investigated.The 4-substituted benzyl bromides have higher reactivity compared with that calculated on the basis of the linear correlations according to the Hammett-Taft equation for unsubstituted and 3-substituted benzyl bromides containing electron-withdrawning substituents.The reactivity of benzyl bromides containing electron-donating substituents obeys a linear correlation with the ?+ constants.The effects of structural changes in the substrate and the nucleophile on the character of the transition states of the investigated reactions is discussed.
CHEMICAL INDUCTION OF POLY-CIS CAROTENOID BIOSYNTHESIS
Poling, Stephen M.,Hsu, Wan-Jean,Yokoyama, Henry
, p. 1677 - 1680 (2007/10/02)
Key Word Index - Citrus paradisi; Rutaceae; Marsh white seedless grapefruit; carotenoid biosynthesis; bioregulators; poly-cis carotenoids; carotenoids; prolycopene.A new class of synthetic bioregulators is reported which cause the accumulation of poly-cis carotenoids in the flavedo of Marsh white seedless grapefruit.The compounds tested were all secondary amines: dibenzylamine, substituted dibenzylamines (4-F; 4-Cl; 4-Br; 2-, 3- and 4-Me; 4-NO2; 4-CN; 4-Cl; 4'-Me; 4-Me, 4'-NO2), N-benzyl phenethylamine and N-benzyl 2-naphthalenemethylamine.The most effective, 4-chlorodibenzylamine, caused the accumulation of 74 μg/g dry wt of poly-cis carotenoids.Prolycopene was the predominant pigment but substantial amounts of proneurosporene, poly-cis-γ-carotenes and other cis carotenes were also present.The mode of action of these new bioregulators is probably gene derepression, the same as that of the lycopene inducers.However, the secondary amines probably derepress a recessive gene governing the biosynthesis of poly-cis carotenoids; whereas, the lycopene inducers derepress the dominant gene that gives rise to the normall all-trans carotenoids.The new compounds did not seem to inhibit the cyclase(s), as the lycopene inducers do.
