104478-93-5Relevant articles and documents
Esterification of Tertiary Amides: Remarkable Additive Effects of Potassium Alkoxides for Generating Hetero Manganese–Potassium Dinuclear Active Species
Akiyama, Shoko,Himo, Fahmi,Hirai, Takahiro,Katayama, Shoichiro,Kato, Daiki,Mai, Binh Khanh,Mashima, Kazushi,Nagae, Haruki
, (2020/07/25)
A catalyst system of mononuclear manganese precursor 3 combined with potassium alkoxide served as a superior catalyst compared with our previously reported manganese homodinuclear catalyst 2 a for esterification of not only tertiary aryl amides, but also tertiary aliphatic amides. On the basis of stoichiometric reactions of 3 and potassium alkoxide salt, kinetic studies, and density functional theory (DFT) calculations, we clarified a plausible reaction mechanism in which in situ generated manganese–potassium heterodinuclear species cooperatively activates the carbonyl moiety of the amide and the OH moiety of the alcohols. We also revealed details of the reaction mechanism of our previous manganese homodinuclear system 2 a, and we found that the activation free energy (ΔG≠) for the manganese–potassium heterodinuclear complex catalyzed esterification of amides is lower than that for the manganese homodinuclear system, which was consistent with the experimental results. We further applied our catalyst system to deprotect the acetyl moiety of primary and secondary amines.
A 4, 4 - dimethoxy - 2, 2 - bipyridyl silver catalytic hydrogenation of aromatic nitro compound synthesis of aromatic amines (by machine translation)
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Paragraph 0016; 0025; 0028, (2017/07/19)
The invention discloses a 4, 4 - dimethoxy - 2, 2 - bipyridyl silver catalytic hydrogenation of aromatic nitro compound synthesis of aromatic amines, the method uses a cheap, easy synthesis of 4, 4 - dimethoxy - 2, 2 - bipyridyl silver as catalyst, in order to green, environmental protection, non-toxic as the hydrogen source, the aromatic nitro compound in the relatively mild reaction conditions, one-step reaction can synthesize aromatic amine. The invention has simple operation, catalyst is cheap and easy and small consumption, mild reaction conditions, to substrate demonstrates better functional group tolerant, high product yield, industrial manufacturing cost, it has very good application prospect. (by machine translation)
Boron trifluoride-methanol complex. Mild and powerful reagent for deprotection of acetylated amines. Scope and selectivity
Miltsov, Sergey,Karavan, Vladimir,Misharev, Alexandr,Alonso-Chamarro, Julian,Puyol, Mar
supporting information, p. 641 - 644 (2016/01/26)
A boron trifluoride-methanol complex demonstrated remarkable deprotection selectivity against commonly used amino-protecting groups in the deacetylation of acetanilides and high sensitivity to the steric hindrance of substrates. The scope and limitations of the reaction were explored.
Water at elevated temperatures (WET): Reactant, catalyst, and solvent in the selective hydrolysis of protecting groups
Medina-Ramos, Wilmarie,Mojica, Mike A.,Cope, Elizabeth D.,Hart, Ryan J.,Pollet, Pamela,Eckert, Charles A.,Liotta, Charles L.
, p. 2147 - 2155 (2014/04/17)
Water at elevated temperatures (WET) can act simultaneously as reactant, solvent, and catalyst in reaction processes. WET has been successfully employed in the removal of protecting groups alleviating the need for added strong acids/bases, subsequent neutralization and waste salt elimination. The protocols for the water-mediated removal of several common protecting groups such as tert-butyl carbamates (N-Boc) from 125 to 150 °C, acetamide (N-Ac) at 275 °C and acetate esters (O-Ac) at 250 °C are reported for different model aryl compounds. In addition, high yields and selective deprotection of one protecting group in the presence of another by simply tuning the temperature is demonstrated. In order to gain further insights into reaction processes, the aqueous solubilities of several of the reactants, the kinetics and mechanisms associated with some of these reactions are also discussed. the Partner Organisations 2014.
A new class of low-molecular-weight amphiphilic gelators
Mohmeyer, Nils,Schmidt, Hans-Werner
, p. 863 - 872 (2007/10/03)
A new powerful class of low-molecular-weight amphiphilic compounds has been synthesized and their structure-property relationships with respect to their gelation ability of organic solvents have been investigated. These compounds are able to gel organic solvents over a broad range of polarity. Especially polar solvents such as valeronitrile and γ-butyrolactone can be gelled even at concentrations far below 1 wt %. It was found that the gelation ability of these asymmetrically substituted p-phenylendiamines depends on a well-balanced relation of the terminal head group, the units involved in hydrogen bonding (amide or urea groups), and on the length of the alkyl chain. With this class of new gelators it is possible to tailor thermal and mechanical properties in different organic solvents and open various application possibilities.
Quinone Imine Route to Benzimidazol-2-ylcarbamates. Part 1. Synthesis of Open-chain and Cyclic 5-Acylamino Derivatives.
Rajappa, Srinivasachari,Sreenivasan, Ramaswami,Khalwadekar, Asha
, p. 1657 - 1675 (2007/10/02)
The synthesis of the N',N''-bismethoxycarbonyl-N-(4-acylaminophenyl)guanidines (4) and (7) is described.Oxidation of these with LTA has led to the benzimidazol-2-ylcarbamates. (8), (9) and (10) through a regiospecific cyclisation of quinone imine intermediates.If the acylamino group is part of a ring, the yield of benzimidazoles (15) increases with the size of the lactam ring.The direction of ring closure may be controlled by electronic and steric factors.
