88460-82-6Relevant academic research and scientific papers
Chemoselective Electrosynthesis Using Rapid Alternating Polarity
Baran, Phil S.,Carlson, Ethan,Edwards, Jacob T.,Hayashi, Kyohei,Kawamata, Yu,Saito, Masato,Shaji, Shobin,Simmons, Bryan J.,Waldmann, Dirk,Zapf, Christoph W.
supporting information, p. 16580 - 16588 (2021/10/20)
Challenges in the selective manipulation of functional groups (chemoselectivity) in organic synthesis have historically been overcome either by using reagents/catalysts that tunably interact with a substrate or through modification to shield undesired sites of reactivity (protecting groups). Although electrochemistry offers precise redox control to achieve unique chemoselectivity, this approach often becomes challenging in the presence of multiple redox-active functionalities. Historically, electrosynthesis has been performed almost solely by using direct current (DC). In contrast, applying alternating current (AC) has been known to change reaction outcomes considerably on an analytical scale but has rarely been strategically exploited for use in complex preparative organic synthesis. Here we show how a square waveform employed to deliver electric current - rapid alternating polarity (rAP) - enables control over reaction outcomes in the chemoselective reduction of carbonyl compounds, one of the most widely used reaction manifolds. The reactivity observed cannot be recapitulated using DC electrolysis or chemical reagents. The synthetic value brought by this new method for controlling chemoselectivity is vividly demonstrated in the context of classical reactivity problems such as chiral auxiliary removal and cutting-edge medicinal chemistry topics such as the synthesis of PROTACs.
Cu(OTf)2catalyzed Ugi-type reaction ofN,O-acetals with isocyanides for the synthesis of pyrrolidinyl and piperidinyl 2-carboxamides
Feng, Yi-Man,Lin, Guo-Qiang,Mao, Zhuo-Ya,Nie, Xiao-Di,Si, Chang-Mei,Wei, Bang-Guo
supporting information, p. 9248 - 9251 (2021/09/20)
The Cu(OTf)2catalyzed Ugi-type reactions ofN,O-acetals with isocyanides have been described for the synthesis of pyrrolidinyl and piperidinyl 2-carboxamides. 4-Hydroxy-5-substituted-prolinamides can be obtained in high diastereoselectivities (2
An alkylidene carbene C-H activation approach toward the enantioselective syntheses of spirolactams: Application to the synthesis of (-)-adalinine
Annadi, Krishna,Wee, Andrew G. H.
, p. 1021 - 1038 (2016/02/19)
A method based on in situ alkylidene carbene generation-C-H insertion reaction of 5-(3-oxobutyl)pyrrolidin-2-ones and 6-(3-oxobutyl)piperidin-2-ones is developed for the enantioselective synthesis of 1-azaspiro[4,4]non-6-ene-2-ones and 6-azaspiro[4,5]dec-1-ene-7-ones. The required 5-(3-oxobutyl)pyrrolidin-2-ones and 6-(3-oxobutyl)piperidin-2-ones are prepared from the Wacker oxidation of internal alkenes typified by 5-(but-2-enyl)pyrrolidin-2-ones and 6-(but-2-enyl)piperidin-2-ones, respectively. Excellent regioselectivity (≥92:8) is realized for the Wacker oxidation, and high yields (78-89%) of the desired lactam ketones are obtained. The results from further investigations into the Wacker oxidation suggested that the high regioselectivity of the oxidation in these lactam alkenes might be due to the participation of the lactam nitrogen via intramolecular coordination to Pd(II) during the reaction. Studies on alkylidene carbene generation-C-H insertion reaction of the lactam ketones revealed that the reaction efficiency is sensitive to the reaction temperature and the amount of lithio(trimethylsilyl)diazomethane employed, which led to the development of optimal reaction conditions for effecting alkylidene carbene generation-C-H insertion. Using the optimal reaction conditions, good to high yields (53-76%) of both γ- and δ-lactam spirocycles were obtained. The synthetic utility of the spirolactams was demonstrated by the synthesis of (-)-adalinine.
General Approach to Nitrogen-Bridged Bicyclic Frameworks by Rh-Catalyzed Formal Carbenoid Insertion into an Amide C-N Bond
Harada, Shingo,Kono, Masato,Nozaki, Tomoyuki,Menjo, Yasuhiro,Nemoto, Tetsuhiro,Hamada, Yasumasa
, p. 10317 - 10333 (2015/11/03)
Various nitrogen-bridged bicyclic skeletons are found in bioactive natural products and pharmaceuticals. The development of a new reaction to construct these molecular frameworks has attracted considerable attention in synthetic organic chemistry. We deve
One-pot synthesis of pyrrolidino- and piperidinoquinolinones by three-component aza-Diels-Alder reactions of in situ generated N-arylimines and cyclic enamides
Zhang, Wei,Zhang, Wenxue,Dai, Yisi,Wang, Xuerui
supporting information; experimental part, p. 6122 - 6126 (2011/12/01)
An efficient synthesis of hexahydropyrrolo[3,2-c]quinolin-2-ones and hexahydropyridino[3,2-c]quinolin-2-ones has been developed in moderate to high yields by one-pot two-step aza-Diels-Alder reactions of N-arylimines, formed in situ from anilines and benz
Synthesis of 2-azabicyclo[4.1.0]heptanes through stereoselective cyclopropanation reactions
Suarez Del Villar, Irene,Gradillas, Ana,Perez-Castells, Javier
, p. 5850 - 5862 (2011/03/17)
Unsaturated δ-lactams are cyclopropanated with the aid of diazo compound decomposition catalysed by metal complexes. A study of the reaction conditions, stereochemical outcome and group protection is reported. The resulting bicyclic products are related to bioactive compounds. Transformation into thiolactams facilitates the separation of the different isomers obtained and the removal of the protecting group. The cyclopropanation reaction works with diverse diazo compounds. Unsaturated δ-lactams are cyclopropanated with the aid of diazo compound decomposition catalysed by metal complexes. A study of the reaction conditions, stereochemical outcome and group protection isreported. Transformation into thiolactams assists in separation of the different isomers obtained and removal of the protecting group.
Unsaturated lactams: New inputs for povarov-type multicomponent reactions
Vicente-Garcia, Esther,Catti, Federica,Ramon, Rosario,Lavilla, Rodolfo
supporting information; body text, p. 860 - 863 (2010/04/29)
Unsaturated lactams with endo- or exocyclic C-C double bonds constitute a set of reactive inputs that serve as the electron-rich olefin component in Povarov reactions. These substrates afford the multicomponent adducts in convenient yields and offer a wid
Lewis acid-promoted tandem desulfurization and hydroxylation of γ-phenylthio-substituted lactams: Novel synthetic strategy of isoindolobenzazepine alkaloid, chilenine
Yoda, Hidemi,Inoue, Kei-Ichi,Ujihara, Yasuaki,Mase, Nobuyuki,Takabe, Kunihiko
, p. 9057 - 9060 (2007/10/03)
Treatment of a variety of alicyclic and aromatic γ-phenylthio- substituted lactams with Lewis acids such as cuprous or cupric halides in aqueous solution at rt was found to undergo novel tandem desulfurization and hydroxylation reactions to generate γ-hydroxylated lactams without the ring-opened products in extremely high yields, respectively. This process was further applied to the total synthesis of an isoindolobenzazepine alkaloid, chilenine, by featuring the elaboration of the functionalized phthalimide derivative.
Base-catalyzed carbon-carbon bond formation reactions of ω-hydroxylactams
Speckamp, W. N.,Boer, J. J. J. de
, p. 410 - 414 (2007/10/02)
Active methylene compounds such as methyl ketones, 1,3-dicarbonyl systems and nitromethane condense under the influence of base with ω-hydroxylactams, thereby forming α-alkylated nitrogen heterocycles.The ease of alkylation is detemined by the position of a tautomeric equilibrium between ω-hydroxylactam and the open-chain amide-aldehyde, which is dependent upon the type of N-substituent and upon the lactam ring size.Some applications for the products obtained are indicated.
