7464-44-0Relevant academic research and scientific papers
Hydrogenation of Secondary Amides using Phosphane Oxide and Frustrated Lewis Pair Catalysis
K?ring, Laura,Sitte, Nikolai A.,Bursch, Markus,Grimme, Stefan,Paradies, Jan
supporting information, p. 14179 - 14183 (2021/09/03)
The metal-free catalytic hydrogenation of secondary carboxylic acid amides is developed. The reduction is realized by two new catalytic reactions. First, the amide is converted into the imidoyl chloride by triphosgene (CO(OCCl3)2) using novel phosphorus(V) catalysts. Second, the in situ generated imidoyl chlorides are hydrogenated in high yields by an FLP-catalyst. Mechanistic and quantum mechanical calculations support an autoinduced catalytic cycle for the hydrogenation with chloride acting as unusual Lewis base for FLP-mediated H2-activation.
σ-Bond Hydroboration of Cyclopropanes
Arifin,Itami, Kenichiro,Kato, Hiroki,Kobayashi, Chisa,Kondo, Hiroki,Matsushita, Kaoru,Miyamura, Shin,Yamaguchi, Junichiro,Yokogawa, Daisuke
supporting information, p. 11306 - 11313 (2020/07/13)
Hydroboration of alkenes is a classical reaction in organic synthesis in which alkenes react with boranes to give alkylboranes with subsequent oxidation resulting in alcohols. The double bond (π-bond) of alkenes can be readily reacted with boranes owing to its high reactivity. However, the single bond (σ-bond) of alkanes has never been reacted. To pursue the development of σ-bond cleavage, we selected cyclopropanes as model substrates since they present a relatively weak σ-bond. Herein, we describe an iridium-catalyzed hydroboration of cyclopropanes, resulting in β-methyl alkylboronates. These unusually branched boronates can be derivatized by oxidation or cross-coupling chemistry, accessing "designer"products that are desired by practitioners of natural product synthesis and medicinal chemistry. Furthermore, mechanistic investigations and theoretical studies revealed the enabling role of the catalyst.
Tert -Butyl nitrite promoted transamidation of secondary amides under metal and catalyst free conditions
Sureshbabu, Popuri,Azeez, Sadaf,Chaudhary, Priyanka,Kandasamy, Jeyakumar
, p. 845 - 850 (2019/01/30)
A mild and efficient method is demonstrated for the transamidation of secondary amides with various amines including primary, secondary, cyclic and acyclic amines in the presence of tert-butyl nitrite. The reaction proceeds through the N-nitrosamide intermediate and provides the transamidation products in good to excellent yields at room temperature. Moreover, the developed methodology does not require any catalyst or additives.
Chemoselective Synthesis of α-Amino-α-cyanophosphonates by Reductive Gem-Cyanation-Phosphonylation of Secondary Amides
Chen, Ting-Ting,Wang, Ai-E,Huang, Pei-Qiang
supporting information, p. 3808 - 3812 (2019/05/24)
A novel approach to α-amino-α-cyanophosphonates has been developed. The method features a Tf2O-mediated reductive geminal cyanation/phosphonylation of secondary amides. Mild reaction conditions, high bond-forming efficiency, inexpensive readily available starting materials, and good to excellent yields with wide functional group compatibility constitute the main advantages of this method. The protocol can be run on a gram scale.
Tf2O-Mediated Intermolecular Coupling of Secondary Amides with Enamines or Ketones: A Versatile and Direct Access to β-Enaminones
Liu, Yong-Peng,Zhu, Cheng-Jie,Yu, Cun-Cun,Wang, Ai-E,Huang, Pei-Qiang
supporting information, p. 7169 - 7174 (2019/11/16)
Based on the Tf2O-mediated intermolecular reaction of secondary amides with enamines derived from ketones, a novel approach to β-enaminones has been developed. The reaction is widely functional group tolerant and highly chemoselective. In the presence of 4 ? molecular sieves, the method can be extended to the one-pot condensation of secondary amides with ketones for NH β-enaminones synthesis.
Towards a Sequential One-Pot Preparation of 1,2,3-Benzotriazin-4(3H)-ones Employing a Key Cp*Co(III)-catalyzed C?H Amidation Step
Chirila, Paula G.,Skibinski, Lauren,Miller, Keith,Hamilton, Alex,Whiteoak, Christopher J.
supporting information, p. 2324 - 2332 (2018/04/30)
1,2,3-benzotriazin-4(3H)-one derivatives have been recognised for their potential application as pesticides and pharmaceuticals and new methodologies for their preparation, starting from readily accessible reagents would therefore be an attractive proposition. A wide range of differently substituted benzamides are readily available, which provide an excellent substrate scaffold for the application of direct C?H functionalization protocols. In this context, herein we report the use of a Cp*Co(III) catalyst for the amidation of these benzamides, using 1,4,2-dioxazol-5-ones as amidating agent. The isolable intermediate 2-acetamido benzamide products can thereafter be converted to the desired 1,2,3-benzotriazin-4(3H)-one derivatives through the use of tert-butyl nitrite under mild conditions. It was found to be possible to perform the second step with the crude reaction mixture obtained from the initial C?H amidation step, leading to the overall development of a facile one-pot procedure for the preparation of a range of substituted 1,2,3-benzotriazin-4(3H)-one derivatives, requiring only 5 hours of reaction time, which is also applicable on a gram scale. In addition, the key Cp*Co(III)-catalyzed C?H amidation step has been studied by DFT calculations in order to fully elucidate the mechanism. (Figure presented.).
Atom economical synthesis of: N -alkylbenzamides via the iron(III) sulfate catalyzed rearrangement of 2-alkyl-3-aryloxaziridines in water and in the presence of a surfactant
Kra?em, Jamil,Ollevier, Thierry
, p. 1263 - 1267 (2017/08/15)
A green and mild synthetic route to N-alkylbenzamides involves eco-friendly one pot synthesis of 2-alkyl-3-aryloxaziridines from N-alkylamines and benzaldehydes followed by iron(iii) sulfate catalyzed rearrangement to the corresponding amides in water as the solvent and in the presence of sodium dodecyl sulfate as the surfactant. This green approach affords N-alkylbenzamides in high overall yields under simple and minimum manipulation.
Appel reaction of carboxylic acids with tribromoisocyanuric acid/triphenylphosphine: A mild and acid-free preparation of esters and amides
Da Cunha Sindra, Haryadylla,De Mattos, Marcio C.S.
, p. 1129 - 1136 (2016/07/06)
A facile and efficient method for esterification and amidation of carboxylic acids under neutral conditions has been developed. Esters and amides can be prepared by reacting a carboxylic acid (1 mmol) with tribromoisocyanuric acid (0.37 mmol) and triphenylphosphine (1 mmol) in dichloromethane at room temperature, followed by addition of an alcohol or an amine, respectively.
Acid mediated deprotection of N-isopropyl tertiary amides
Lorenc, Chris,Reeves, Jonathan T.,Busacca, Carl A.,Senanayake, Chris H.
, p. 1280 - 1282 (2015/03/04)
Tertiary amides containing an N-isopropyl group were selectively deprotected by heating in methanesulfonic acid. The N-isopropyl group was removed selectively in the presence of other groups on the amide nitrogen such as methyl, primary alkyl, or aryl. The putative isopropyl cation was trapped by Friedel-Crafts alkylation of anisole when the latter was included as a co-solvent.
A mild, copper-catalysed amide deprotection strategy: Use of tert-butyl as a protecting group
Evans, Vikki,Mahon, Mary F.,Webster, Ruth L.
supporting information, p. 7593 - 7597 (2014/12/10)
Mild methods for the deprotection of organic substrates are of fundamental importance in synthetic chemistry. A new room temperature method using a catalytic amount of Cu(OTf)2is reported. This allows use of the tert-butyl group as an amide protecting group. The methodology is also extended to Boc-deprotection.
