3271-81-6Relevant academic research and scientific papers
PCl3-mediated transesterification and aminolysis of tert-butyl esters via acid chloride formation
Wu, Xiaofang,Zhou, Lei,Li, Fangshao,Xiao, Jing
, p. 491 - 497 (2021/01/20)
A PCl3-mediated conversion of tert-butyl esters into esters and amides in one-pot under air is developed. This novel protocol is highlighted by the synthesis of skeletons of bioactive molecules and gram-scale reactions. Mechanistic studies revealed that this transformation involves the formation of an acid chloride in situ, which is followed by reactions with alcohols or amines to afford the desired products.
Development of a triazinedione-based dehydrative condensing reagent containing 4-(dimethylamino)pyridine as an acyl transfer catalyst
Liu, Jie,Fujita, Hikaru,Kitamura, Masanori,Shimada, Daichi,Kunishima, Munetaka
supporting information, p. 4712 - 4719 (2021/06/11)
A new triazinedione-based reagent, (N,N′-dialkyl)triazinedione-4-(dimethylamino)pyridine (ATD-DMAP) was developed for the operationally simple dehydrative condensation of carboxylic acids. This reagent comprises an ATD core and DMAP as the leaving group, which is liberated into the reaction system to accelerate acyl transfer reactions. Upon adding ATD-DMAP to a mixture of carboxylic acids and alcohols in the presence of an amine base, the corresponding esters were formed rapidly at room temperature. Moreover, dehydrative condensation between carboxylic acids and amines using ATD-DMAP proceeded in high yield.
Efficiency Enhancement of a Photocatalytic Decarbonylation of an Aminocyclopropenone by Benzothiophene Substitution
Mishiro, Kenji,Nomura, Mitsuki,Furuyama, Taniyuki,Kunishima, Munetaka
, p. 3625 - 3636 (2021/03/03)
To improve the efficiency of the photocatalytic decarbonylation of cyclopropenones, the effects of substituents on cyclopropenone were explored. A benzothiophene-substituted aminocyclopropenone exhibited significantly improved decarbonylation efficiency t
Tungsten-Catalyzed Transamidation of Tertiary Alkyl Amides
Feng, Fang-Fang,Liu, Xuan-Yu,Cheung, Chi Wai,Ma, Jun-An
, p. 7070 - 7079 (2021/06/30)
Transamidation has recently emerged as a straightforward and convenient means to diversify amides. However, the kinetically and thermodynamically demanding transamidation of notoriously robust, fully alkyl-substituted tertiary amides still remains a longstanding challenge. Here, we describe a method for the activation of tertiary alkyl amides to streamline transamidation using simple tungsten(VI) chloride as a catalyst and chlorotrimethylsilane as an additive. The highly electrophilic and oxophilic tungsten catalyst enables the selective scission of a C-N bond of tertiary alkyl amides to effect transamidation of a myriad of structurally and electronically diverse tertiary alkyl amides and amines. Mechanistic study implies that the synergistic effect of the catalyst and the additive could pronouncedly induce the nucleophilic acyl substitution of tertiary alkyl amide with amine to realize transamidation.
Practical one-pot amidation of N -Alloc-, N -Boc-, and N -Cbz protected amines under mild conditions
Hong, Wan Pyo,Tran, Van Hieu,Kim, Hee-Kwon
, p. 15890 - 15895 (2021/05/19)
A facile one-pot synthesis of amides from N-Alloc-, N-Boc-, and N-Cbz-protected amines has been described. The reactions involve the use of isocyanate intermediates, which are generated in situ in the presence of 2-chloropyridine and trifluoromethanesulfonyl anhydride, to react with Grignard reagents to produce the corresponding amides. Using this reaction protocol, a variety of N-Alloc-, N-Boc-, and N-Cbz-protected aliphatic amines and aryl amines were efficiently converted to amides with high yields. This method is highly effective for the synthesis of amides and offers a promising approach for facile amidation.
Visible-Light Decatungstate/Disulfide Dual Catalysis for the Hydro-Functionalization of Styrenes
Prieto, Alexis,Taillefer, Marc
supporting information, p. 1484 - 1488 (2021/03/08)
We describe an efficient photoredox system, relying on decatungstate/disulfide catalysts, for the hydrofunctionalization of styrenes. In this methodology the use of disulfide as a cocatalyst was shown to be crucial for the reaction efficiency. This photoredox system was employed for the hydro-carbamoylation, -acylation, -alkylation, and -silylation of styrenes, giving access to a large variety of useful building blocks and high-value molecules such as amides and unsymmetrical ketones from simple starting materials.
Solar and visible-light active nano Ni/g-C3N4photocatalyst for carbon monoxide (CO) and ligand-free carbonylation reactions
Hosseini-Sarvari, Mona,Akrami, Zahra
, p. 956 - 969 (2021/02/26)
In this study, we investigate the amino and alkoxycarbonylation reaction between various substituted aryl halides, benzyl iodides, and iodocyclohexane with different types of amines and alcohols in the absence of carbon monoxide gas and ligands. Similar reactions are carried out at high temperatures, in the presence of appropriate ligands, stoichiometric amounts of bases, and gaseous carbon monoxide, which endanger the health of organic chemists. We present a novel method that does not utilize ligands, bases, gaseous CO, and special conditions. This procedure is a redox reaction carried out by new economic nano Ni/g-C3N4at room temperature and under visible light. Mo(CO)6was used toin situgenerate CO, to resolve the problems caused by the use of CO gas. This protocol has the ability to be used on a gram scale by using a continuous flow reactor.
Asymmetric Markovnikov Hydroaminocarbonylation of Alkenes Enabled by Palladium-Monodentate Phosphoramidite Catalysis
Yao, Ya-Hong,Yang, Hui-Yi,Chen, Ming,Wu, Fei,Xu, Xing-Xing,Guan, Zheng-Hui
, p. 85 - 91 (2021/01/12)
A palladium-catalyzed asymmetric Markovnikov hydroaminocarbonylation of alkenes with anilines has been developed for the atom-economical synthesis of 2-substituted propanamides bearing an α-stereocenter. A novel phosphoramidite ligand L16 was discovered which exhibited very high reactivity and selectivity in the reaction. This asymmetric Markovnikov hydroaminocarbonylation employs readily available starting materials and tolerates a wide range of functional groups, thus providing a facile and straightforward method for the regio- and enantioselective synthesis of 2-substituted propanamides under ambient conditions. Mechanistic studies revealed that the reaction proceeds through a palladium hydride pathway.
Hypervalent Iodine Reagent-Promoted Hofmann-Type Rearrangement/Carboxylation of Primary Amides
Wang, Xia,Yang, Peng,Hu, Bo,Zhang, Qian,Li, Dong
, p. 2820 - 2826 (2021/02/01)
A novel transformation of primary amides to secondary amides promoted by hypervalent iodine reagents was developed. The hypervalent iodine reagent-mediated Hofmann-type rearrangement generated an isocyanate intermediate, which was subsequently trapped by an in situ generated carboxylic acid from the hypervalent iodine reagent to provide the corresponding secondary amides. This method provided a facile and efficient route for the synthesis of secondary amides from primary amides and also revealed novel reactivities of hypervalent iodine reagents.
Chromium-catalyzed ligand-free amidation of esters with anilines
Chen, Changpeng,Ling, Liang,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 762 - 766 (2021/04/14)
Amides are important structural motifs in pharmaceutical and agrochemical chemistry because of the intriguing biological active properties. We report here the amidation of commercially available esters with anilines that was promoted by low-cost and air-stable chromium(III) pre-catalyst combined with magnesium, providing access to amides. This reaction occurs without the use of external ligands in a simple operation. Mechanistic studies indicate that a reactive aminated Cr species responsible for the amidation can be considered, which may be formed by reaction of low-valent Cr with aniline followed by reduction with hydrogen evolution.
