Refernces
10.1021/jo00021a014
The research focuses on the modification of the Bischler-Napieralski reaction for the synthesis of 3-aryl-3,4-dihydroisoquinolines. The purpose of this study was to address the inefficiencies of the traditional Bischler-Napieralski reaction in synthesizing 3-arylisoquinolines, which are important intermediates for the synthesis of various isoquinoline alkaloids and potential medicinal agents. The researchers successfully developed a method that avoids the elimination of the amide group as a nitrile via the retro-Ritter reaction by converting it to an N-acyliminium intermediate with oxalyl chloride-FeCl3. This modification resulted in the formation of 3,4-dihydroisoquinolines in moderate to high yields. The chemicals used in the process include (1,2-diphenylethyl)amides, oxalyl chloride, FeCl3, and various amide derivatives such as formamide, acetamide, benzamide, and phenylacetamide. The study concluded that this new method offers a highly effective synthetic route for the asymmetric synthesis of natural products and medicinal agents containing the 3-arylisoquinoline ring system and provides an alternative, mild method for the preparation of simple 3,4-dihydroisoquinolines.
10.1007/s10593-008-0140-3
The research aimed to efficiently synthesize a series of 3-arylisoquinolin-1(2H)-ones, which are nitrogen analogues of isocoumarins and are found in various bioactive natural products. These compounds have therapeutic value, exhibiting activities such as antidepressant, anti-inflammatory, and analgesic properties. The study focused on converting 3-substituted isocoumarins into their nitrogen analogues by refluxing with methanamide. The process was successful, yielding isoquinolin-1(2H)-ones in 76–85% yield and high purity. The chemicals used in this process included 3-substituted isocoumarins (1a-j) and methanamide, with the reaction progress monitored by TLC, and the products characterized by comparing their mp, IR, 1H NMR, and mass spectral data with those of the corresponding isocoumarins. The conclusion of the research was that a one-pot conversion of 3-substituted isocoumarins to the corresponding isoquinolones was achieved, demonstrating a synthetically feasible procedure for accessing these bioactive heterocycles.
10.1021/ol100387h
The study explores a one-pot procedure for transforming arynes into ortho-disubstituted arenes using formamides and dialkylzincs. Arynes, being highly strained and unstable intermediates, are utilized as electrophiles in this organic synthesis. Formamides, specifically N,N-dimethylformamide (DMF), serve as the carbonyl compounds that react with arynes, facilitating the insertion into the carbonyl group. Dialkylzincs, such as Et2Zn, Me2Zn, and Ph2Zn, act as organometallic reagents to trap the intermediates generated from the insertion process, leading to the formation of ortho-disubstituted arenes. The study investigates various conditions, including different fluoride ion sources and solvents, to optimize the reaction yield and regioselectivity. The results show that the sequential reaction proceeds smoothly via the trapping of quinone methide intermediates derived from the formal [2 + 2] cycloaddition adducts, with high chemical efficiency and regioselectivity under optimized conditions.
10.1016/j.tet.2018.03.048
The study focuses on the selective synthesis of 1,4,5-trisubstituted imidazoles from α-imino ketones, which are prepared through N-heterocyclic-carbene (NHC)-catalyzed aroylation of imidoyl chlorides with aromatic aldehydes. The research outlines a straightforward methodology that involves NHC-catalyzed aroylation, followed by chemoselective reduction of the imino group, and subsequent annulation with formamide to form the imidazole ring. This approach allows the rapid and regioselective synthesis of imidazole derivatives with potential applications in pharmaceuticals and agrochemicals. The study demonstrates the substrate scope and optimization of reaction conditions, highlighting the importance of this method in creating chemical libraries for further application.
10.1002/anie.201604921
The study presents a novel method for transforming alcohols into chlorides, amines, and ethers using formamides as Lewis base catalysts. The key chemicals involved are formamides, which act as catalysts, and benzoyl chloride (BzCl), which serves as the sole reagent for the transformation. The method is highly efficient, with excellent functional group tolerance, scalability, and a favorable waste balance (E-factor down to 2). The process proceeds through iminium-activated alcohol intermediates and can be performed under solvent-free conditions. Enantioenriched alcohols (99% ee) are converted with high stereoselectivity into the corresponding chlorides. The study also demonstrates a one-pot procedure where the initially formed chlorides can be further transformed into amines, azides, ethers, sulfides, and nitriles, highlighting the method's versatility and potential for synthesizing bioactive compounds.
T
