61364-70-3Relevant academic research and scientific papers
Pd-Catalyzed Asymmetric Acyl-Carbamoylation of an Alkene to Construct an α-Quaternary Chiral Cycloketone
Liu, Min,Wang, Xing,Guo, Ziqiong,Li, Hanyuan,Huang, Wei,Xu, Hui,Dai, Hui-Xiong
supporting information, p. 6299 - 6304 (2021/08/30)
Herein, we report the palladium-catalyzed asymmetric acyl-carbamoylation of an alkene by employing thioesters as the acyl electrophiles and t-BuNC as the carbamoyl reagent, affording an α-quaternary chiral cycloketone in synthetically useful yields with excellent enantioselectivity. The reaction proceeded via asymmetric 1,2-migratory insertions of acyl-Pd into alkenes and subsequent migratory insertion of isocyanides into C(sp3)-PdII. The product could be diversified to some valuable skeletons with retention of enantiopurity, demonstrating the synthetic utility of this protocol.
Visible-light-promoted radical alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester: Synthesis of oxazolines
Ding, Hao,Huang, Panyi,Jin, Can,Su, Weike,Sun, Bin,Yan, Zhiyang,Zhao, Haiyun
supporting information, (2021/10/29)
An efficient photocatalytic alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester has been developed. The transformation is taken advantage of alkyl radicals to attack allylic amide with the assist of inexpensive rose bengal as photocatalyst to prepare a series of alkyl substituted oxazolines in moderate to excellent yields. High regioselectivity, operational safety, mild conditions and excellent substrate generality give this protocol broad application prospects.
An Aliphatic Bischler-Napieralski Reaction: Dihydropyridones by Cyclocarbonylation of 3-Allylimidazolidin-4-ones
Amer, Mostafa M.,Olaizola, Olatz,Carter, Jennifer,Abas, Hossay,Clayden, Jonathan
supporting information, p. 253 - 256 (2020/01/02)
The N-chloroformylimidazolidinone derivative of enantiopure l-alanine was deprotonated to form an enolate and functionalized with a series of allylic halides. Treatment of the resulting carbamoyl chlorides with potassium iodide led to cyclization of the allylic substituent onto the carbonyl group in an intramolecular aliphatic Friedel-Crafts-type acylation that corresponds to an aliphatic Bischler-Napieralski reaction. The product 3,4-dihydropyridinones were amenable to further functionalization, and finally hydrolysis, to deliver a series of enantio-enriched pipecolic acid derivatives.
Construction of Various Bridged Polycyclic Skeletons by Palladium-Catalyzed Dearomatization
Mu, Xingye,Peng, Henian,Tang, Wenjun,Wu, Ting,Xiong, Wenrui,Yu, Hanxiao
supporting information, p. 8143 - 8147 (2020/03/24)
A powerful palladium-catalyzed dearomative cyclization was developed that provides facile access to eight types of bridged tetracyclic skeletons bearing various ring sizes and heterocycles. With this method, several skeletons or analogues of natural products, including tubingensin B and dracaenones, were synthesized. Asymmetric dearomative cyclization enables the construction of various enantiomerically enriched bridged polycyclic systems with up to 99 % ee by employing a chiral palladium catalyst.
Highly Enantioselective Iridium-Catalyzed Hydrogenation of 2-Aryl Allyl Phthalimides
Cabré, Albert,Romagnoli, Elia,Martínez-Balart, Pol,Verdaguer, Xavier,Riera, Antoni
supporting information, p. 9709 - 9713 (2019/11/19)
The iridium-catalyzed asymmetric hydrogenation of 2-aryl allyl phthalimides to afford enantioenriched β-aryl-β-methyl amines is presented. Recently developed Ir-MaxPHOX catalysts are used for this enantioselective transformation. The mild reaction conditions and the feasible removal of the phthalimido group makes this catalytic method easily scalable and of great interest to afford chiral amines. The importance of this new methodology is exemplified by the formal synthesis of (R)-Lorcaserin, OTS514, and enantiomerically enriched 3-methyl indolines.
A Copper Catalyst with a Cinchona-Alkaloid-Based Sulfonamide Ligand for Asymmetric Radical Oxytrifluoromethylation of Alkenyl Oximes
Li, Xi-Tao,Gu, Qiang-Shuai,Dong, Xiao-Yang,Meng, Xiang,Liu, Xin-Yuan
supporting information, p. 7668 - 7672 (2018/05/30)
A copper-catalyzed asymmetric radical oxytrifluoromethylation of alkenyl oxime and Togni's reagent has been successfully developed, thereby providing straightforward access to CF3-containing isoxazolines bearing α-tertiary stereocenters with excellent yield and enantioselectivity. The key to success is the rational design of cinchona-alkaloid-based sulfonamides as neutral/anionic hybrid ligands to effectively control the stereochemistry in copper-catalyzed reactions involving free alkyl radical species. The utility of this method is illustrated by efficient transformation of the products into useful chiral CF3-containing 1,3-aminoalcohols.
Copper-catalyzed radical oxytrifluoromethylation of alkenyl oximes at ambient temperature
Li, Xi-Tao,Lv, Ling,Gu, Qiang-Shuai,Liu, Xin-Yuan
supporting information, p. 6041 - 6046 (2018/09/11)
A mild and efficient copper-catalyzed radical oxytrifluoromethylation reaction of alkenyl oximes was successfully developed. The method provides a straightforward access to a wide range of CF3-containing isoxazolines in good to excellent yields.
Chelation versus Non-Chelation Control in the Stereoselective Alkenyl sp2 C?H Bond Functionalization Reaction
Liang, Qiu-Ju,Yang, Chao,Meng, Fei-Fan,Jiang, Bing,Xu, Yun-He,Loh, Teck-Peng
supporting information, p. 5091 - 5095 (2017/04/24)
A hydroxy group chelation-assisted stereospecific oxidative cross-coupling reaction between alkenes was developed under mild reaction conditions. In the presence of palladium catalyst, the alkenes tethered with hydroxy functionality can couple efficiently with electron-deficient alkenes to form the corresponding multi-substituted olefin products. The hydroxy group on the substrate could play dual roles in reaction, acting as the directing group for alkenyl C?H bond activation and controlling the stereoselectivity of the products.
Synthesis of 2,5-Diaryl-1,5-dienes from Allylic Bromides Using Visible-Light Photoredox Catalysis
Pratsch, Gerald,Overman, Larry E.
, p. 11388 - 11397 (2015/12/01)
Visible-light photoreductive coupling of 2-arylallyl bromides in the presence of the photocatalyst Ru(bpy)3(PF6)2, a Hantzsch ester, and i-Pr2NEt gives 2,5-diaryl-1,5-dienes in high yield. This method avoids the use of stoichiometric metal reductants and is compatible with the presence of halogen, alkyl, electron-donating, and electron-withdrawing substituents on the aromatic ring.
Highly enantioselective Rh-catalyzed hydrogenation of β,γ- unsaturated phosphonates with chiral ferrocene-based monophosphoramidite ligands
Duan, Zheng-Chao,Hu, Xiang-Ping,Zhang, Cheng,Wang, Dao-Yong,Yu, Sai-Bo,Zheng, Zhuo
supporting information; experimental part, p. 9191 - 9194 (2010/03/04)
(Chemical Equation Presented) An enantioselective synthesis of chiral alkylphosphonates bearing a β-stereogenic center, based on the Rh-catalyzed asymmetric hydrogenation of corresponding β-substituted β,γ-unsaturated phosphonates with a ferrocene-based monophosphoramidite ligand under the mild hydrogenation conditions, was developed, in which an ee value of up to 98% was obtained.
