共查询到20条相似文献,搜索用时 390 毫秒
1.
Teruhisa Tsuchimoto Hirokazu Utsugi Tetsuya Sugiura Shin Horio 《Advanced Synthesis \u0026amp; Catalysis》2015,357(1):77-82
Under zinc Lewis acid catalysis, terminal alkynes coupled dehydrogenatively with 1,8‐naphthalenediaminatoborane [HB(dan)]. It is important to note that the resulting alkynylboranes with an C(sp) B(dan) bond are isolable by column chromatography on silica gel (SiO2) and are usable as coupling partners for palladium‐ and copper‐catalyzed cross‐coupling reactions with (hetero)aryl halides.
2.
Michal Drusan Erik Rakovský Jaromír Marek Radovan ebesta 《Advanced Synthesis \u0026amp; Catalysis》2015,357(7):1493-1498
Asymmetric catalytic multistep reactions enable the formation of structurally complex compounds from simple starting materials. Enantioselective Cu‐catalyzed 1,4‐additions of Grignard reagents to Michael acceptors form reactive chiral enolates. We show here that these chiral enolates react in a one‐pot fashion with naked carbenium ions, such as tropylium, 1,3‐benzodithiolium, and dianisylmethylium ions. The corresponding products were obtained in good yields, with enantioselectivities up to 96% ee and high diastereomeric purities.
3.
Benedikt Reichart Gema GuedesdelaCruz Klaus Zangger C. Oliver Kappe Toma Glasnov 《Advanced Synthesis \u0026amp; Catalysis》2016,358(1):50-55
A copper(II)/NafionNR50‐catalyzed cascade is demonstrated, wherein in situ keteneimine formation and hydroarylation processes are involved. Various substituted 4‐sulfonamidoquinolin‐2‐ones and various derivatives thereof were obtained. The robust toluenesulfonamide protecting group can be removed on demand in a mild light‐promoted process to provide access to otherwise difficult to obtain 4‐aminoquinolin‐2‐ones.
4.
The chiral benzofuranone structural motif is a prominent feature in many natural products, which exhibit a broad range of biological and pharmaceutical activities. In the past few years, a survey of chiral benzofuranone derivatives based on asymmetric catalysis reveals an increasing number of papers, which reflects the latest achievements to facilitate the synthesis of sufficient quantities of related compounds as potential medicinal agents and biological probes. Recent advances in this area are summarized and classified according to the structure of the starting substrate.
5.
Yona Lee Seungpyeong Heo Sung‐Gon Kim 《Advanced Synthesis \u0026amp; Catalysis》2015,357(7):1545-1550
A synthetic method for the construction of fully substituted enantioenriched 1,4‐dihydroquinolines using an organocatalytic aza‐Michael/Michael cascade reaction has been developed. The asymmetric reaction of 2‐(tosylamino)phenyl α,β‐unsaturated ketones with alkynyl aldehydes, promoted by diphenylprolinol O‐TMS ether as an organocatalyst, generated chiral 1,4‐dihydroquinolines in good to high yields with excellent enantioselectivities (up to 97 % ee).
6.
7.
Ke‐Feng Zhang Jing Nie Ran Guo Yan Zheng Jun‐An Ma 《Advanced Synthesis \u0026amp; Catalysis》2013,355(17):3497-3502
An enantioselective aza‐Friedel–Crafts (F‐C) reaction of indoles with cyclic N‐acylketimines has been developed. By using chiral phosphoric acid catalysts, a wide range of enantioenriched trifluoromethyldihydroquinazolines was obtained in excellent yields (up to 98%) with good to high enantioselectivities (up to 99% ee).
8.
Hai‐Bin Yang Yun‐zhou Zhao Rui Sang Yin Wei Min Shi 《Advanced Synthesis \u0026amp; Catalysis》2014,356(18):3799-3808
Hydroquinine anthraquinone‐1,4‐diyl diether [(DHQ)2AQN]‐catalyzed unprecedented asymmetric domino annulation reactions of acylidenoxindoles/isatins, acylidenoxindoles and allenoates are disclosed in this communication, providing a facile access to hexahydrofuro[2,3‐b]furans containing four contiguous chiral centers in good to excellent yields along with good to excellent ee values and moderate to good dr values. Based on theoretical investigations, a concerted [3+2] ring‐closure process was proposed, in which steric hindrance and π–π stacking interaction between catalyst and substrate subtly co‐control the diastereoselectivity of the reaction.
9.
A synthetically useful 1,3‐insertion reaction of a rhodium‐carbenoid into the C(sp2) H bond of simple indole is disclosed, which produces structurally divergent 2‐indolylenamides in good to excellent yields and decent chemo‐ and regioselectivities. The obtained tryptamine vinylogues can be transformed into biologically important tryptamine derivatives or 3,3′‐biindoles with ease.
10.
Man Liu Duanyang Kong Meina Li Guofu Zi Guohua Hou 《Advanced Synthesis \u0026amp; Catalysis》2015,357(18):3875-3879
A highly efficient, iridium‐catalyzed, enantioselective hydrogenation of β,β‐disubstituted nitroalkenes has been developed. Using a complex consisting of iridium and (S,S)‐f‐spiroPhos as the catalyst, a variety of β,β‐disubstituted nitroalkenes were successfully hydrogenated to the corresponding chiral nitroalkanes with excellent enantioselectivities (up to 98% ee) and high turnover numbers (TON=1000).
11.
Jianlin Zhang Yulong Zhang Xiaohua Liu Jing Guo Weidi Cao Lili Lin Xiaoming Feng 《Advanced Synthesis \u0026amp; Catalysis》2014,356(17):3545-3550
An enantioselective protonation by means of chiral scandium complex‐catalyzed aza‐Michael reaction was realized. A series of α‐aryl‐substituted vinyl ketones reacted with pyrazoles smoothly, affording the corresponding enantiomerically enriched pyrazole derivatives with excellent results (up to 99% yield, 94% ee). Water and hydrogen chloride were found to accelerate the protonation process.
12.
Catalytic Cross‐Coupling of Vinyl Golds with Diazonium Salts under Photoredox and Thermal Conditions
Dilip V. Patil Hokeun Yun Senghoon Shin 《Advanced Synthesis \u0026amp; Catalysis》2015,357(12):2622-2628
Catalytically generated vinyl gold complexes from tert‐butyl allenoates were found to undergo an efficient cross‐coupling with arenediazonium salts. The gold(I)‐gold(III) redox cycle can be accessed under two different conditions, i.e., visible‐light photoredox as well as a thermally induced radical chain pathway. The current C(sp2) C(sp2) cross‐coupling protocol that is catalytic in gold, would make available desirable structural diversity to the traditional cross‐coupling chemistry.
13.
Highly regio‐ and diastereoselective 1,2‐addition of organolithium reagents to chiral fluoroalkyl α,β‐unsaturated N‐tert‐butanesulfinyl ketimines was developed, providing a general and efficient method for the asymmetric synthesis of structurally diverse α‐tertiary fluoroalkyl allylic amines in high yields and with excellent diastereoselectivities (dr up to>99:1). The synthetic application of the method was demonstrated by the rapid and convenient preparation of challenging α‐fluoroalkyl α‐amino acids with α‐tetrasubstituted carbon.
14.
Feihua Luo Jun Yang Zhengkai Li Haifeng Xiang Xiangge Zhou 《Advanced Synthesis \u0026amp; Catalysis》2016,358(6):887-893
A palladium(II)‐catalyzed direct arylation of methylene C(sp3) H bonds by 2‐methyl‐7‐aminobenzoxazole as an effective auxiliary is reported. This process exhibited high beta‐site selectivity, broad substrate scope, and compatibility with different functional groups with moderate to high yields up to 89%.
15.
Chuanli Ren Feng Wei Qingqing Xuan Dong Wang Li Liu 《Advanced Synthesis \u0026amp; Catalysis》2016,358(1):132-137
A direct enantioselective reaction of cyclopent‐2‐enone‐derived Morita–Baylis–Hillman alcohols with 4‐hydroxycoumarins has been developed under the catalysis of a chiral primary amine derived from cinchonine in combination with a Brønsted acid. The reaction provides pyranocoumarin products with three vicinal chiral carbon centers in highly regio‐, diastereo‐ and enantioselectivities through a tandem allylic alkylation/intramolecular oxa‐Michael addition.
16.
The first catalytic asymmetric dearomatization of 3‐methyl‐2‐vinylindoles has been established by using quinone monoimides as suitable electrophiles in the presence of chiral phosphoric acid, which afforded chiral indole derivatives bearing a quaternary stereogenic center in a chemospecific and highly enantioselective fashion (up to 81% yield, >99% ee). The success of this reaction was enabled by the reactivity switch of 3‐methyl‐2‐vinylindoles, which has not been reported before. This reaction also represents the first catalytic asymmetric arylative dearomatization of vinylindoles, which will help confront the challenges in catalytic asymmetric arylative dearomatization and dearomatization of vinylindoles.
17.
Rafa Kowalczyk Przemysaw J. Boratyski 《Advanced Synthesis \u0026amp; Catalysis》2016,358(8):1289-1295
Organocatalyzed highly stereoselective 1,4‐thia‐Michael addition of mercaptans to linear 2,4‐dienones and 2‐en‐4‐ynones was developed using Cinchona alkaloid‐based squaramides. Application of only 0.5–1 mol % loading afforded products in up to 98:2 e.r. and above 99:1 after a single recrystallization. The adducts of allyl mercaptan can be conveniently further transformed to new chiral 2‐substituted 2,5‐dihydrothiophenes by ring‐closing metathesis.
18.
Hiroyuki Miyamura Aya Suzuki Tomohiro Yasukawa Sh Kobayashi 《Advanced Synthesis \u0026amp; Catalysis》2015,357(18):3815-3819
We have achieved an integrated process of oxidation–olefination–asymmetric 1,4‐addition reactions under aerobic and aqueous conditions using metal nanoparticles as robust heterogeneous catalysts. A tandem process of aerobic oxidation and Horner–Wadsworth–Emmons olefination was successfully catalyzed by gold/palladium bimetallic nanoparticles. A wide range of substrates gave the desired products in high yields and excellent selectivities. This tandem process was further connected with an asymmetric 1,4‐addition reaction catalyzed by chiral rhodium nanoparticles to achieve a challenging three‐step, one‐pot sequential reaction. Various types of esters with a chiral center at the β‐position were obtained from readily available and stable alcohols and arylboronic acids in high yields with high enantioselectivities in a one‐pot sequential reaction integrating three transformations.
19.
Jaya KishoreVandavasi Wan‐Ping Hu Gopal ChandruSenadi Hui‐Ting Chen Hsing‐Yin Chen Kuang‐Chan Hsieh Jeh‐Jeng Wang 《Advanced Synthesis \u0026amp; Catalysis》2015,357(13):2788-2794
A mild and efficient transition metal‐free approach has been developed for the synthesis of highly substituted chiral morpholines from alkenols by amino acid‐derived iodine(III) reagents via a 6‐exo‐trig cyclization. The key features of this work include the formation of three chiral centers with a high diastereomeric ratio, broad functional group compatibility, and atom/time economic methodology.
20.
Houssein Ibrahim Pierre deFrmont Pierre Braunstein Vincent Thry Lionel Nauton Federico Cisnetti Arnaud Gautier 《Advanced Synthesis \u0026amp; Catalysis》2015,357(18):3893-3900
Water‐soluble gold(III/I) N‐heterocylic carbene complexes behave as efficient catalysts for the hydration of terminal alkynes in neat water. The transformation proceeds in the absence of Brønsted acids or halide scavengers and is suitable for sensitive substrates. Kinetic profiles and DFT studies provide a clear picture of intermediates present during catalysis.