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1.
Chenggui Wu Zhenxing Liu Zhikun Zhang Fei Ye Guisheng Deng Yan Zhang Jianbo Wang 《Advanced Synthesis \u0026amp; Catalysis》2016,358(15):2480-2488
A new synthetic method for α‐alkynyl‐α,β‐unsaturated esters is presented herein. The method is based on a copper(I)‐catalyzed three‐component reaction of a terminal alkyne, diazoesters and aldehydes. The reaction is featured by mild conditions, high yields and excellent stereoselectivity. Cu(I) carbene migratory insertion is proposed as the key step in the transformation.
2.
Hui Zhu Weiwei Jin Jiayao He Yan Zhang Gangguo Zhu 《Advanced Synthesis \u0026amp; Catalysis》2016,358(23):3730-3735
A regio‐ and stereoselective method for the synthesis of (E)‐α,β‐unsaturated carbonyls has been developed via a silver‐catalyzed tandem epoxide rearrangement/intermolecular carbonyl‐heteroalkyne metathesis. Various heteroalkynes including ynol ethers, ynamides, and thioalkynes work well for this transformation, leading to the production of (E)‐α,β‐unsaturated esters, amides, and thioesters in moderate to excellent yields with good functional group compatibility. It represents one of the rare examples of regio‐ and stereoselective intermolecular alkyne‐carbonyl metathesis (ACM).
3.
Bilal Ahmad Mir Arghya Banerjee Sourav Kumar Santra Suresh Rajamanickam Bhisma K. Patel 《Advanced Synthesis \u0026amp; Catalysis》2016,358(21):3471-3476
An iron(III)‐catalyzed C‐3 functionalization of flavones has been achieved using tert‐butyl peroxybenzoate (TBPB)/potassium persulphate (K2S2O8) oxidant combinations with a suitable solvent. In the presence of iron(III)/tert‐butyl peroxybenzoate/potassium persulphate, the reaction of flavones in cycloalkanes afforded exclusive C‐3 cycloalkylation via C –C coupling, whereas the solvent N,N‐dialkylformamide provided C‐3 amidation via C –C coupling. Under identical reaction conditions just by switching the solvent to chlorobenzene, C‐3 methylated flavones were obtained where tert‐butyl peroxybenzoate (TBPB) served as the source of the methyl group.
4.
Nai‐Kai Li Ling‐Pei Kong Zheng‐Hang Qi Shao‐Jie Yin Jun‐Qi Zhang Bing Wu Xing‐Wang Wang 《Advanced Synthesis \u0026amp; Catalysis》2016,358(19):3100-3112
Several chiral BINOL‐derived bisoxazoline (BOX)/copper(II) complexes were synthesized and evaluated as catalysts for the Friedel–Crafts reaction of indoles with isatin‐derived β,γ‐unsaturated α‐keto esters. The resulting bis‐indole products bearing a quaternary stereocenter were obtained in excellent yields and enantioselectivities. Additionally, the desired products were practically transformed to α‐amino esters, α‐hydroxy esters and α‐keto amides. It is noteworthy that this catalytic procedure was conducted with a catalyst loading of 0.5 mol% without any discernible decrease in the reactivity or enantioselectivity.
5.
A new strategy for the synthesis of fluorovinyl acetates and β,β‐difluoro carboxylates using a hypervalent iodine and hydrogen fluoride‐based fluorination reagent is established through a silver‐catalyzed one‐pot reaction involving formation of carbon‐oxygen and carbon‐nitrogen bonds. The generated fluoroalkenes substituted with the carbon‐oxygen and carbon‐nitrogen bond on the β‐position have the potential to be transformed into various products which would be difficult to obtain via direct fluorination.
6.
Pankaj Chauhan Suruchi Mahajan Uur Kaya Arto Valkonen Kari Rissanen Dieter Enders 《Advanced Synthesis \u0026amp; Catalysis》2016,358(20):3173-3178
An efficient asymmetric synthesis of spirocyclohexenone β‐lactams bearing three contiguous stereocenters has been achieved in moderate to good yields and high stereoselectivities. The protocol involves the combination of a squaramide‐catalyzed sulfa‐Michael addition under desymmetrization via a dynamic kinetic resolution of racemic 2,5‐cyclohexadienones.
7.
Yoshinari Sawama Masahiro Masuda Ryosuke Nakatani Hiroki Yokoyama Yasunari Monguchi Toshifumi Dohi Yasuyuki Kita Hironao Sajiki 《Advanced Synthesis \u0026amp; Catalysis》2016,358(23):3683-3687
The iron(III) chloride‐catalyzed Friedel–Crafts arylation of 4‐aryl‐4‐methoxy‐2,5‐cyclohexadienones, which were easily prepared by the phenyliodine(III) diacetate (PIDA)‐mediated oxidation of 4‐arylphenols in methanol, proceeded site‐selectively to form meta‐terphenyl (2,4‐diarylphenol) derivatives in good yields. The subsequent PIDA‐mediated oxidation and iron(III) chloride‐catalyzed Friedel–Crafts arylation of the resulting products gave the corresponding 2,4,6‐triarylphenol derivatives. The present method provides useful highly substituted polyarylated compounds.
8.
Sara Meninno Chiara Volpe Alessandra Lattanzi 《Advanced Synthesis \u0026amp; Catalysis》2016,358(17):2845-2848
A highly enantioselective one‐pot synthesis of important building blocks, α‐chiral γ‐keto esters, has been developed by combining a quinine‐catalyzed Michael addition of malononitrile to trans‐enones followed by magnesium monoperoxyphthalate (MMPP) oxidation. These synthons proved to be useful reagents for a simple access to challenging cis‐α,γ‐disubstituted γ‐butyrolactones in good diastereoselectivity and high enantiocontrol.
9.
Xiaoting Wu Fang Xie Zheng Ling Liang Tang Wanbin Zhang 《Advanced Synthesis \u0026amp; Catalysis》2016,358(15):2510-2518
A regio‐ and enantioselective copper‐catalyzed 1,4‐conjugate addition of trimethylaluminium to linear δ‐aryl‐substituted α,β,γ,δ‐unsaturated alkyl ketones was developed. A series of γ,δ‐unsaturated alkyl ketones were obtained in good yields with high regio‐ and enantioselectivity (up to 88% ee and 96:4 dr). Expansion of the reaction scope to substrates containing aromatic heterocycles also afforded good yields and enantioselectivities (up to 91% ee) with very high regioselectivities, exclusively providing the single 1,4‐products.
10.
Valrian Gob Maxime Dousset Pascal Retailleau Vincent Gandon Xavier Guinchard 《Advanced Synthesis \u0026amp; Catalysis》2016,358(24):3960-3965
N‐Allyltetrahydro‐β‐carbolines bearing a pendant allene undergo unprecedented gold(I)‐catalyzed cyclizations proceeding with an allyl migration from the nitrogen to the allene moiety. The initial product of the gold‐catalyzed cyclization evolves either via isomerization or Cope rearrangement, leading to different scaffolds. Density function theory (DFT) calculations established that the allyl migration occurs in an asynchronous suprafacial manner.
11.
Yi Wei Ran Guo Yanfeng Dang Jing Nie Jun‐An Ma 《Advanced Synthesis \u0026amp; Catalysis》2016,358(17):2721-2726
A convenient organocatalytic enantioselective decarboxylative Michael addition of β‐keto acids to dicyanoolefins and disulfonylolefins is realized. In the presence of saccharide‐derived chiral amino thioureas, the reaction proceeded smoothly to afford a wide range of the Michael adducts in 62–99% yield with 70–94% ee. Moreover, one of the chiral adducts obtained could be readily converted into the monofluorinated product in a total 68% yield over four steps with 85% ee.
12.
Pratheepkumar Annamalai Wu‐Yin Chen Selvam Raju Kou‐Chi Hsu Nitinkumar Satyadev Upadhyay Chien‐Hong Cheng Shih‐Ching Chuang 《Advanced Synthesis \u0026amp; Catalysis》2016,358(22):3642-3648
Palladium‐catalyzed cycloaromatization of N‐acyl‐2‐aminobiaryls, through a sequence of ortho C−H bond activation/alkyne insertion/meta C−H bond activation/alkyne insertion, was developed. An efficient synthesis of multiaryl‐substituted naphthalenes, N‐[2‐(5,6,7,8‐tetraarylnaphthalen‐1‐yl)aryl]acetamides, was demonstrated using molecular oxygen as the sole oxidant. Furthermore, through Buchwald's synthetic protocol, two compounds were converted into corresponding fluorescent carbazoles in 30–40% yield by intramolecular C−N bond formation.
13.
Valentin Magn Florent Blanchard Angela Marinetti Arnaud Voituriez Xavier Guinchard 《Advanced Synthesis \u0026amp; Catalysis》2016,358(21):3355-3361
N‐Propargyl‐ and N‐homoallenyl‐2‐bromo‐β‐tryptamines undergo gold(I)‐catalyzed dearomatizing cyclizations to afford 2‐bromospiroindolenines that are in situ hydrolyzed to furnish spirooxindoles in a one‐pot process. Tryptophane derivatives (R2=CO2Et) led upon cyclization to chiral spirooxindoles in excellent diastereoselectivities.
14.
Nitinkumar Satyadev Upadhyay Jayachandran Jayakumar Chien‐Hong Cheng 《Advanced Synthesis \u0026amp; Catalysis》2016,358(21):3381-3386
A highly regioselective synthesis of pyrido[2,1‐a]isoindolium salts from 2‐arylpyridines and two equivalents of electron‐deficient alkenes catalyzed by rhodium is demonstrated. The reaction was carried out in aqueous medium at 110 °C using inexpensive oxygen as oxidant. Reverse aza‐Michael addition of the isoindolium salt occurs when the salt was treated with base to give a β‐disubstituted alkene product. A reaction mechanism involving an ortho C–H olefination of 2‐arylpyridine by alkene, intramolecular aza‐Michael addition, deprotonation at the β‐carbon of the alkene fragment followed by another Michael addition to give the final product is proposed.
15.
Michela Beltrani Carla Carfagna Barbara Milani Raffaella Mancuso Bartolo Gabriele Francesco Fini 《Advanced Synthesis \u0026amp; Catalysis》2016,358(20):3244-3253
The straightforward in situ synthesized bis(2,6‐diisopropyl)acenaphthenequinonediimine palladium triflate catalyst was generally employed for both the mono‐alkoxycarbonylation of terminal alkynes, and the bis‐alkoxycarbonylation of 1,2‐disubstituted alkynes by using mild reaction conditions [carbon monoxide pressure (PCO)=4 bar, temperature=20 °C]. Utilizing low catalyst loading (down to 0.5 mol%), a variety of propiolic esters were synthesized with good to excellent isolated yields. Most importantly the system was very efficient not only with methanol but also with a range of different alcohols, starting from the less hindered benzyl alcohol to the most hindered ones, such as isopropyl alcohol and tert‐butyl alcohol. In addition, aromatic and aliphatic 1,2‐disubstituted alkynes were converted into maleic acid derivatives, together with an acid‐catalyzed isomerization reaction, showing modest to good selectivity and excellent combined yields. In particular 3‐hexyne showed a satisfactory degree of selectivity for the maleic diesters of methanol and benzyl alcohol, obtaining the corresponding products with good isolated yields.
16.
Danila Gasperini Lorenzo Maggi Stphanie Dupuy Richard M. P. Veenboer David B. Cordes Alexandra M. Z. Slawin Steven P. Nolan 《Advanced Synthesis \u0026amp; Catalysis》2016,358(23):3857-3862
The improved synthesis of γ‐, δ‐ and ϵ‐lactones using a dinuclear N‐heterocyclic carbene (NHC)‐gold(I) catalyst is reported. This solvent‐free process provides access to γ‐ and δ‐lactones in high regio‐ and stereoselectivity. Reactions were performed at low catalyst loadings and without the need for any additives. The use of a digold pre‐catalyst provides a new synthetic route to functionalised ϵ‐lactones, poorly accessible using previous methodologies.
17.
Kristína Plevov Liang Chang Emmeline Martin Quentin Llopis Luc Dechoux Serge Thorimbert 《Advanced Synthesis \u0026amp; Catalysis》2016,358(20):3293-3297
An efficient regio‐ and stereoselective metal‐catalyzed addition of two Grignard reagents (homo‐coupling, 2 RMgX or hetero‐coupling, R1MgX+R2MgX) to methyl coumalate (methyl 2‐oxo‐2H‐pyran‐5‐carboxylate) is described. This synthetic approach opens the access to a wide variety of functionalized β,γ‐unsaturated carboxylic acids in a modular way. Control of the chemo‐ and stereoselectivity of this one‐pot procedure is discussed.
18.
Chun‐Ming Chan Zhongyuan Zhou Wing‐Yiu Yu 《Advanced Synthesis \u0026amp; Catalysis》2016,358(24):4067-4074
A rhodium(III)‐catalyzed cycloaddition of N‐tert‐butoxycarbonylhydrazones with internal alkynes was developed. The reaction features a regioselective α‐imino alkyl C(sp3)−H bond functionalization resulting in selective formation of highly functionalized NH‐free pyrroles. Our studies showed that utilizing the N‐tert‐butoxycarbonyl (N‐Boc) as the oxidizing directing group is critical for achieving the observed pyrrole formation versus the isoquinoline formation. To account for the pyrrole formation, we hypothesized that a prior tautomerization of the N‐Boc‐hydrazones to enamines should occur, followed by regioselective C(sp2)–H cleavage to form a putative five‐membered rhodacycle. Subsequent coupling of the rhodacycle with the alkynes would afford the pyrrole products.
19.
Chun‐Lin Zhang Zhong‐Hua Gao Zhi‐Qin Liang Song Ye 《Advanced Synthesis \u0026amp; Catalysis》2016,358(18):2862-2866
An oxidative NHC‐catalyzed [2+4] annulation of enals and α‐cyano‐β‐methylenones was established for the rapid assembly of multi‐substituted benzenes.
20.
《Advanced Synthesis \u0026amp; Catalysis》2017,359(7):1157-1163
A user‐friendly, calcium(II)‐ and copper(II)‐catalyzed one‐pot reaction sequence to furnish cyclopenta[b ]pyrroles with a high level of complexity is depicted. The reaction involves the following sequential transformations: (i) an aza‐Piancatelli cyclization, (ii) a hydroamination/isomerization process and (iii) a subsequent Friedel–Crafts‐type reaction to afford the desired compounds from readily available 2‐furylcarbinols, anilines and secondary alcohols with a minimum of precautions.