13294-34-3Relevant academic research and scientific papers
Amination of aryl- and vinylacetylenic compounds catalyzed by rhodium(I) complexes
Costa,Chiusoli,Gaetti,Gabriele,Salerno
, p. 936 - 940 (1998)
New rhodium-catalyzed amination reactions of arylacetylenes and cyclohexen-1-ylacetylene in the presence of strong bases with the use of carbon dioxide as an auxiliary are described. Secondary amines attack the terminal carbon atom of the triple bond followed by protonation of the adjacent carbon atom. Alternatively, the reaction can proceed further with the addition of the second alkyne molecule. The conditions for the selective synthesis of enamines (up to 87% yield) or α-substituted propynylamines (up to 86% yield) are reported.
Anti-Selective Organocatalytic Michael Addition between Phenylacetaldehyde and Nitrostyrene
Donadío, Lucía Gandolfi,Galetti, Mariana A.,Giorgi, Gianluca,Rasparini, Marcello,Comin, Maria J.
, p. 7952 - 7957 (2016)
Using the reaction between phenylacetaldehyde and nitrostyrene catalyzed by pyrrolidine as a simple model, we have studied the diastereochemical outcome of the organocatalytic Michael reactions between benzylic aldehydes and nitrostyrenes. We found that t
The pyrrole ring η2-hapticity bridged binuclear tricarbonyl Mo(0) and W(0) complexes: catalysis of regioselective hydroamination reactions and DFT calculations
Jha, Vikesh Kumar,Mani, Ganesan,Davuluri, Yogeswara Rao,Anoop, Anakuthil
, p. 1840 - 1847 (2017)
Following the report of the ferrocene structure, metal complexes containing the heteroatom-substituted cyclopentadienyl (Cp) analogue, that is the η5 pyrrolyl ligand, have been reported. While the Cp ligand continues to be a favorite ligand in
B(C6F5)3-catalyzed tandem protonation/deuteration and reduction of: In situ -formed enamines
Wu, Rongpei,Gao, Ke
, p. 4032 - 4036 (2021/05/19)
A highly efficient B(C6F5)3-catalyzed tandem protonation/deuteration and reduction of in situ-formed enamines in the presence of water and pinacolborane was developed. Regioselective β-deuteration of tertiary amines was achieved with high chemo- and regioselectivity. D2O was used as a readily available and cheap source of deuterium. Mechanistic studies indicated that B(C6F5)3 could activate water to promote the protonation and reduction of enamines. This journal is
Revisiting the role of acids and hydrogen bond acceptors in enamine formation
Hammond, Gerald B.,Lu, Zhichao,Xu, Bo
supporting information, p. 6849 - 6852 (2020/10/02)
A systematic investigation into the effects of acids and hydrogen bond acceptors on the reaction rates and equilibria of enamine formation is reported. Acids can accelerate the reaction but do not change the reaction equilibria. In comparison, hydrogen bond acceptors facilitate the enamine formation via their strong hydrogen bonding interaction with the water generated in the reaction.
Selective N1/N4 1,4-Cycloaddition of 1,2,4,5-Tetrazines Enabled by Solvent Hydrogen Bonding
Zhu, Zixi,Glinkerman, Christopher M.,Boger, Dale L.
supporting information, p. 20778 - 20787 (2020/12/22)
An unprecedented 1,4-cycloaddition (vs 3,6-cycloaddition) of 1,2,4,5-tetrazines is described with preformed or in situ generated aryl-conjugated enamines promoted by the solvent hydrogen bonding of hexafluoroisopropanol (HFIP) that is conducted under mild reaction conditions (0.1 M HFIP, 25 °C, 12 h). The reaction constitutes a formal [4 + 2] cycloaddition across the two nitrogen atoms (N1/N4) of the 1,2,4,5-tetrazine followed by a formal retro [4 + 2] cycloaddition loss of a nitrile and aromatization to generate a 1,2,4-triazine derivative. The factors that impact the remarkable change in the reaction mode, optimization of reaction parameters, the scope and simplification of its implementation through in situ enamine generation from aldehydes and ketones, the reaction scope for 3,6-bis(thiomethyl)-1,2,4,5-tetrazine, a survey of participating 1,2,4,5-tetrazines, and key mechanistic insights into this reaction are detailed. Given its simplicity and breath, the study establishes a novel method for the simple and efficient one-step synthesis of 1,2,4-triazines under mild conditions from readily accessible starting materials. Whereas alternative protic solvents (e.g., MeOH vs HFIP) provide products of the conventional 3,6-cycoladdition, the enhanced hydrogen bonding capability of HFIP uniquely results in promotion of the unprecedented formal 1,4-cycloaddition. As such, the studies represent an example of not just an enhancement in the rate or efficiency of a heterocyclic azadiene cycloaddition by hydrogen bonding catalysis but also the first to alter the mode (N1/N4 vs C3/C6) of cycloaddition.
Direct Catalytic Reductive N-Alkylation of Amines with Carboxylic Acids: Chemoselective Enamine Formation and further Functionalizations
Trillo, Paz,Adolfsson, Hans
, p. 7588 - 7595 (2019/08/20)
Direct reductive N-alkylation of secondary amines with carboxylic acids using molybdenum hexacarbonyl (5 mol %) as catalyst and diethoxymethylsilane as reducing agent generate enamines in a straightforward fashion in high yields. The formed enamines are without the need for isolation or purification further reacted with trimethylsilyl cyanide in the same reaction flask to yield α-amino nitriles in good yields. In the optimized reaction conditions equimolar amounts of carboxylic acid and amine are reacted under neat conditions, and a catalytic amount of trifluoroethanol (0.1 mol %) is added along with TMSCN for the cyanation step. The reductive N-alkylation reaction is demonstrated to be highly chemoselective, tolerating a multitude of different functional groups present in the starting carboxylic acids and amines. The reaction is scalable and the generated α-amino nitriles are converted to other useful compounds, e.g., α-amino acids or amino-tetrazoles. In addition, the intermediate enamines are further transformed into triazolines, sulfonylformamidines, pyrimidinediones, and TMS-propargylamines, respectively, in high yields under mild reaction conditions. Benzoic acids react with secondary amines under similar conditions to give tertiary amines in high yields, and using this methodology, the biologically active compound Piribedil was isolated in 80% yield in a direct one-pot reaction setup.
One-Pot Construction of 1-Phenylchromeno[3,4- b]pyrrol-4(3 H)-one: Application to Total Synthesis of Ningalin B and a Pyrrolocoumarin-Based Electrochromic Switch
Wu, Chun-Ku,Weng, Zhiqiang,Yang, Ding-Yah
supporting information, p. 5225 - 5228 (2019/07/08)
An efficient construction of 1-phenylchromeno[3,4-b]pyrrol-4(3H)-one via coupling of 1-styrylpyrrolidine and 4-chloro-3-nitrocoumarin as a key step is reported. This reaction is further applied to the total synthesis of the natural product ningalin B in f
METHOD FOR PRODUCING FLUORINE-CONTAINING COMPOUND
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Paragraph 0101-0104; 0110-0112, (2019/10/15)
PROBLEM TO BE SOLVED: To provide a method for producing a fluorine-containing compound by the addition reaction of an olefin to a perfluoroalkyl radical, which can be performed industrially in a more suitable manner. SOLUTION: A method for producing a flu
Enamines as Surrogates of Alkene Carbanions for the Reductive Alkenylation of Secondary Amides: An Approach to Allylamines
Wang, Ai-E,Yu, Cun-Cun,Chen, Ting-Ting,Liu, Yong-Peng,Huang, Pei-Qiang
supporting information, p. 999 - 1002 (2018/02/23)
A new strategy to construct allylamines through reductive alkenylation of secondary amides with enamines is reported. The method features the use of trifluoromethanesulfonic anhydride as an activation reagent of amides, and enamines as unconventional alkenylation reagents. In this manner, enamines serve as surrogates of alkene carbanions instead of the classical enolates equivalents. A possible mechanism involving a Hoffmann-like elimination of the amine-borane complex intermediate is proposed.
