- Synthesis of 3,4-bis(Butylselanyl)selenophenes and 4-alkoxyselenophenes promoted by oxone
-
We describe herein an alternative transition-metal-free procedure to access 3,4-bis(butylsela nyl)selenophenes and the so far unprecedented 3-(butylselanyl)-4-alkoxyselenophenes. The protocol involves the 5-endo-dig electrophilic cyclization of 1,3-diynes promoted by electrophilic organosele-nium species, generated in situ through the oxidative cleavage of the Se-Se bond of dibutyl diselenide using Oxone as a green oxidant. The selective formation of the title products was achieved by controlling the solvent identity and the amount of dibutyl diselenide. By using 4.0 equiv of dibutyl diselenide and acetonitrile as solvent at 80?C, four examples of 3,4-bis(butylselanyl)selenophenes were obtained in moderate to good yields (40–78%). When 3.0 equiv of dibutyl diselenide were used, in the presence of aliphatic alcohols as solvent/nucleophiles under reflux, 10 3-(butylselanyl)-4-alkoxyselenophenes were selectively obtained in low to good yields (15–80%).
- Hellwig, Paola S.,Guedes, Jonatan S.,Barcellos, Angelita M.,Perin, Gelson,Lenard?o, Eder J.
-
supporting information
(2021/05/28)
-
- Synthesis of Chiral Propargylamines, Chiral 1,2-Dihydronaphtho[2,1-b]furans and Naphtho[2,1-b]furans with C-Alkynyl N,N′-di-(tert-butoxycarbonyl)-aminals and β-Naphthols
-
Chiral phosphoric acid-catalyzed couplings of C-alkynyl N,N′-di-(tert-butoxycarbonyl)-aminals with β-naphthols led to chiral propargylamines in moderate to high yields with high to excellent enantioselectivity, in which the reactions underwent sequential chiral phosphoric acid-catalyzed in situ formation of N-(tert-butoxycarbonyl)-imines (N-Boc-imines) from the aminals, and 1,2-addition of β-naphthols to the N-Boc-imines. Chiral 1,2-dihydronaphtho[2,1-b]furans and naphtho[2,1-b]furans were prepared with satisfactory results when 10 mol% AgOAc and 20 mol% 2,6-lutidine or 1.2 equiv. of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were added to the resulting chiral propargylamines solution, respectively.
- Man, Ningning,Li, Yuming,Jie, Jiyang,Li, Hongyun,Yang, Haijun,Zhao, Yufen,Fu, Hua
-
supporting information
p. 12884 - 12889
(2021/07/28)
-
- Selective Rhodium-Catalyzed Hydroformylation of Terminal Arylalkynes and Conjugated Enynes to (Poly)enals Enabled by a π-Acceptor Biphosphoramidite Ligand
-
The hydroformylation of terminal arylalkynes and enynes offers a straightforward synthetic route to the valuable (poly)enals. However, the hydroformylation of terminal alkynes has remained a long-standing challenge. Herein, an efficient and selective Rh-catalyzed hydroformylation of terminal arylalkynes and conjugated enynes has been achieved by using a new stable biphosphoramidite ligand with strong π-acceptor capacity, which affords various important E-(poly)enals in good yields with excellent chemo- and regioselectivity at low temperatures and low syngas pressures.
- Zhao, Jiangui,Zheng, Xueli,Tao, Shaokun,Zhu, Yuxin,Yi, Jiwei,Tang, Songbai,Li, Ruixiang,Chen, Hua,Fu, Haiyan,Yuan, Maolin
-
supporting information
p. 6067 - 6072
(2021/08/16)
-
- A Radical-Initiated Fragmentary Rearrangement Cascade of Ene-Ynamides to [1,2]-Annulated Indoles via Site-Selective Cyclization
-
Straightforward access to [1,2]-annulated indoles, key substructures in natural products, is highly desirable yet challenging. Herein, a radical triggered fragmentary cyclization cascade reaction of ene-ynamides is presented, providing a rapid access into [1,2]-annulated indoles by an intermolecular radical addition, intramolecular cyclization, desulfonylative aryl migration, and site-selective C(sp2)-N cyclization sequence. DFT calculations support oxidation of N-centered radical species to cations prior to the C-N bond formation, followed by an unusual aza-Nazarov cyclization.
- Li, Sifan,Wang, Yu,Wu, Zibo,Shi, Weiliang,Lei, Yibo,Davies, Paul W.,Shu, Wei
-
p. 7209 - 7214
(2021/09/14)
-
- Pd-Catalyzed Indole Synthesis via C-H Activation and Bisamination Sequence with Diaziridinone
-
This work describes an efficient Pd-catalyzed indole synthesis. A wide variety of indoles can be obtained in good yields from readily available vinyl bromides. The reaction likely proceeds through a sequential aryl C-H activation and bisamination of a resulting pallada(II)cycle with diaziridinone.
- Wang, Jianjun,Sun, Xiaofeng,Hu, Daguo,Shi, Yian
-
supporting information
p. 7561 - 7565
(2021/10/02)
-
- N -tert-butyl -2 -phenylindole derivative Preparation method and application
-
The invention belongs to the technical field of organic synthesis, and particularly relates to N - tert-butyl -2 -phenyl indole derivatives as well as a preparation method and application thereof. The preparation method comprises the following steps: (Z)-1 - bromo -1 - phenyl -2 - styrene derivative, N, N - di-tert-butyl diazepinone, palladium catalyst, monophosphine ligand, hydrocarbon activator, base and first solvent, and N -tert-butyl -2 -aryl indole derivatives which can synthesize substituent type diversity, and the prepared N -tert-butyl -2 -aryl indole derivative can be used for preparing biologically active molecules N -2 .
- -
-
Paragraph 0184-0188
(2021/11/26)
-
- Expedient Synthesis of Bridged Bicyclic Nitrogen Scaffolds via Orthogonal Tandem Catalysis
-
Bridged nitrogen bicyclic skeletons have been accessed via unprecedented site- and diastereoselective orthogonal tandem catalysis from readily accessible reactants in a step economic manner. Directed Pd-catalyzed γ-C(sp3)-H olefination of aminocyclohexane with gem-dibromoalkenes, followed by a consecutive intramolecular Cu-catalyzed amidation of the 1-bromo-1-alkenylated product delivers the interesting normorphan skeleton. The tandem protocol can be applied on substituted aminocyclohexanes and aminoheterocycles, easily providing access to the corresponding substituted, aza- and oxa-analogues. The Cu catalyst of the Ullmann-Goldberg reaction additionally avoids off-cycle Pd catalyst scavenging by alkenylated reaction product. The picolinamide directing group stabilizes the enamine of the 7-alkylidenenormorphan, allowing further product post functionalizations. Without Cu catalyst, regio- and diastereoselective Pd-catalyzed γ-C(sp3)-H olefination is achieved.
- Bheemireddy, Narendraprasad Reddy,Biswas, Sovan,Evano, Gwilherm,Maes, Bert U. W.,Van Steijvoort, Ben F.,Waeterschoot, Marjo
-
supporting information
p. 21988 - 21996
(2021/08/13)
-
- The hydrodebromination of 1,1-dibromoalkenes via visible light catalysis
-
Vinyl bromides are versatile synthetic intermediates and widely applied in organic synthesis and pharmaceuticals. Herein, a hydrodebromination reaction of 1,1-dibromoalkenes was established via visible light catalysis. A variety of structurally different vinyl bromides were obtained in moderate to excellent yields.
- Sun, Wencheng,Teng, Qiaoling,Cheng, Dongping,Li, Xiaonian,Xu, Xiaoliang
-
supporting information
(2019/12/05)
-
- Electrochemical intramolecular C-H/N-H functionalization for the synthesis of isoxazolidine-fused isoquinolin-1(2: H)-ones
-
A general and practical protocol for the construction of isoxazolidine-fused isoquinolin-1(2H)-ones has been described by electrochemical-oxidation-induced intramolecular annulation via amidyl radicals. In an undivided cell, isoquinolinones could be easily generated from various available amides bearing CONHOR groups under metal-free, additive-free and external oxidant-free conditions. Moreover, this transformation proceeded smoothly by using cheap 95% ethanol as the green solvent and could be extended to the gram scale.
- Zhang, Lin-Bao,Geng, Rui-Sen,Wang, Zi-Chen,Ren, Guang-Yi,Wen, Li-Rong,Li, Ming
-
supporting information
p. 16 - 21
(2020/01/13)
-
- Copper-catalyzed (4+1) and (3+2) cyclizations of iodonium ylides with alkynes
-
The copper(ii)-catalyzed (4+1) cyclizations and copper(i)-catalyzed (3+2) cycloadditions of iodonium ylides and alkynes were successfully developed by employing efficient and safe iodonium ylides instead of traditional diazo compounds. Highly functionaliz
- Liang, Hao,He, Xiaobo,Zhang, Yaqi,Chen, Bin,Ouyang, Jia-Sheng,Li, Yongsu,Pan, Bendu,Subba Reddy, Chitreddy V.,Chan, Wesley Ting Kwok,Qiu, Liqin
-
p. 11429 - 11432
(2020/10/12)
-
- Cs2CO3-Mediated Vicinal Thiosulfonylation of 1,1-Dibromo-1-Alkenes with Thiosulfonates: An Expedient Synthesis of (E)-1,2-Thiosulfonylethenes
-
A new and highly efficient vicinal thiosulfonylation of 1,1-dibromo-1-alkenes with thiosulfonates in the presence of cesium carbonate has been developed. The metal-free diheterofunctionalization is an operationally simple to access a wide range of (E)-1,2-thiosulfonylethenes (α-aryl-β-thioarylvinyl sulfones) in moderate to high yields with high levels of stereoselectivities. Further, scalable reactions have been demonstrated for this transformation, thus illustrating its efficiency and practicality. (Figure presented.).
- Reddy, Raju Jannapu,Kumari, Arram Haritha,Kumar, Jangam Jagadesh,Nanubolu, Jagadeesh Babu
-
supporting information
p. 1587 - 1591
(2019/02/16)
-
- Efficient Access to Chiral β-Borylated Carboxylic Esters via Rh-Catalyzed Hydrogenation
-
Rh/bisphosphine?thiourea ligand (ZhaoPhos)-catalyzed asymmetric hydrogenation of (Z)-β-substituted-β-boryl-α,β-unsaturated esters was successfully developed, furnishing a variety of chiral β-borylated carboxylic esters with high yields and excellent enantioselectivities (up to 99% yield and >99% ee). The gram-scale asymmetric hydrogenation was performed efficiently in the presence of only 0.05 mol% (S/C=2 000) catalyst loading with full conversion, 99% yield and 99% ee. Moreover, the hydrogenation product was easily converted to other versatile synthetic intermediates, such as methyl (S)-3-hydroxy-3-phenylpropanoate and methyl (S)-3-(furan-2-yl)-3-phenylpropanoate. (Figure presented.).
- Liu, Gang,Li, Anqi,Qin, Xueyuan,Han, Zhengyu,Dong, Xiu-Qin,Zhang, Xumu
-
supporting information
p. 2844 - 2848
(2019/04/26)
-
- Synthesis of Chiral β-Borylated Carboxylic Esters via Nickel-Catalyzed Asymmetric Hydrogenation
-
The highly efficient Ni-catalyzed asymmetric hydrogenation of β-boronic ester substituted-α,β-unsaturated carboxylic esters was successfully developed using (S,S)-Ph-BPE as the ligand. A series of chiral β-borylated carboxylic esters were obtained with high yields (94%-99% yields) and excellent enantioselectivities (89%-99% ee). The gram-scale asymmetric hydrogenation with a low catalyst loading (0.25 mol %) and synthetic transformation of hydrogenation product demonstrated the great synthetic utility of this methodology.
- Han, Zhengyu,Liu, Gang,Zhang, Xianghe,Li, Anqi,Dong, Xiu-Qin,Zhang, Xumu
-
supporting information
p. 3923 - 3926
(2019/06/14)
-
- Construction of Phenanthrenes and Chrysenes from β-Bromovinylarenes via Aryne Diels-Alder Reaction/Aromatization
-
A highly efficient transition-metal-free general method for the synthesis of polycyclic aromatic hydrocarbons like phenanthrenes and chrysenes (and tetraphene) from β-bromovinylarenes and arynes has been developed. The reactions proceed via an aryne Diels-Alder (ADA) reaction, followed by a facile aromatization. This is the first report on direct construction of chrysenes (and tetraphene) using the ADA approach. Unlike the literature method which is limited to only 9/10-substituted derivatives, this method gives access to a wide variety of functionalized phenanthrenes.
- Singh, Vikram,Verma, Ram Subhawan,Khatana, Anil K.,Tiwari, Bhoopendra
-
supporting information
p. 14161 - 14167
(2019/10/28)
-
- Dual nickel- and photoredox-catalyzed reductive cross-coupling of aryl vinyl halides and unactivated tertiary alkyl bromides
-
A novel reductive cross-coupling of aryl vinyl halides and unactivated tertiary alkyl bromides has been realized via photoredox/nickel dual catalysis to produce vinyl arene derivatives bearing all-carbon quaternary centers with excellent E-selectivity. A stoichiometric metal reductant could be avoided by employing commercially available N,N,N′,N′-tetramethylethylenediamine (TMEDA) as the terminal reductant.
- Yu, Weijie,Chen, Long,Tao, Jiasi,Wang, Tao,Fu, Junkai
-
supporting information
p. 5918 - 5921
(2019/05/27)
-
- Metal-free synthesis of imidazole by BF3·Et2O promoted denitrogenative transannulation of N-sulfonyl-1,2,3-triazole
-
BF3·Et2O promoted metal-free denitrogenative transannulation of N-sulfonyl-1,2,3-triazole was reported. Rather than transition metals, BF3·Et2O was employed for the first time to promote the formation of α-diazoimines from N-sulfonyl-1,2,3-triazoles in nitriles, leading to the synthesis of various imidazoles. The protocol tolerates a broad range of functional groups and could also be applied to the late-stage modification of bioactive molecules, demonstrating the potential of this protocol in organic synthesis. A plausible mechanism was proposed.
- Yang, Dongdong,Shan, Lihong,Xu, Ze-Feng,Li, Chuan-Ying
-
supporting information
p. 1461 - 1464
(2018/03/08)
-
- Direct Cross-Coupling of Allylic C(sp3)?H Bonds with Aryl- and Vinylbromides by Combined Nickel and Visible-Light Catalysis
-
An efficient protocol for the direct allylic C(sp3)?H bond activation of unactivated tri- and tetrasubstituted alkenes and their functionalization with aryl- and vinylbromides by nickel and visible-light photocatalysis has been developed. The method allows C(sp2)?C(sp3) formation under mild reaction conditions with good functional-group tolerance and excellent regioselectivity.
- Huang, Long,Rueping, Magnus
-
supporting information
p. 10333 - 10337
(2018/07/31)
-
- Nickel(ii)-catalyzed tandem C(sp2)-H bond activation and annulation of arenes with gem-dibromoalkenes
-
A nickel(ii)/silver(i)-catalyzed tandem C(sp2)-H activation and intramolecular annulation of arenes with dibromoalkenes has been successfully achieved, which offers an efficient approach to the 3-methyleneisoindolin-1-one scaffold. Attractive features of this system include its low cost, ease of operation, and its ability to access a wide range of isoindolinones.
- Shi, Yun,Li, Meng-Sheng,Zhang, Fangdong,Chen, Baohua
-
p. 28668 - 28675
(2018/08/29)
-
- Silver-catalyzed Double Decarboxylative Radical Alkynylation/Annulation of Arylpropiolic Acids with α-keto Acids: Access to Ynones and Flavones under Mild Conditions
-
Ynones are privileged building blocks in various organic syntheses of heterocyclic derivatives due to their multifunctional nature, and flavones are an important class of natural products with a wide range of biological activities. We describe the catalytic double decarboxylative alkynylation of arylpropiolic acids with α-keto acids. With Ag(I)/persulfate as the catalysis system, the valuable ynones bearing various substituents could be easily obtained. The introduction of hydroxyl substituent on ortho-site of α-keto acids make this strategy further applicable to the construction of flavone derivatives via heteroannulation in moderate to good yields with a similar silver-catalyzed system. The reactions proceed under relatively mild reaction conditions and tolerate a wide variety of functional groups. Control experiments indicated that both the reactions undergo radical processes. (Figure presented.).
- Meng, Mengting,Wang, Guofang,Yang, Liangfeng,Cheng, Kai,Qi, Chenze
-
supporting information
p. 1218 - 1231
(2018/02/16)
-
- Synthesis of o-Allyloxy(ethynyl)benzene Derivatives by Cu-Catalyzed Suzuki–Miyaura-Type Reaction and Their Transformations into Heterocyclic Compounds
-
We have found that Suzuki–Miyaura-type reactions of o-allyloxy(bromoethynyl)benzenes with arylboronic acids using a hydrazone/Cu catalyst system proceeded smoothly in iPrOH under mild conditions to afford the corresponding o-allyloxy(arylethynyl)benzene derivatives in good yields without decomposition of the allyloxy group. We have further demonstrated that annulation and enyne metathesis of the o-allyloxy(arylethynyl)benzene derivatives using transition-metal catalysts led to various heterocyclic compounds.
- Watanabe, Kohei,Mino, Takashi,Ishikawa, Eri,Okano, Miyu,Ikematsu, Tatsuya,Yoshida, Yasushi,Sakamoto, Masami,Sato, Kazuki,Yoshida, Kazuhiro
-
supporting information
p. 2359 - 2368
(2017/05/01)
-
- Synthesis of ent-[3]-Ladderanol: Development and Application of Intramolecular Chirality Transfer [2+2] Cycloadditions of Allenic Ketones and Alkenes
-
An enantioselective synthesis of ent-[3]-ladderanol is presented. The ladderanes are an interesting class of molecules for their unique structure of fused cyclobutane rings as well as their perceived biological function of organism protection. The route h
- Line, Nathan J.,Witherspoon, Brittany P.,Hancock, Erin N.,Brown, M. Kevin
-
supporting information
p. 14392 - 14395
(2017/10/24)
-
- Nickel-Catalyzed Reductive Cross-Coupling of Vinyl Bromides with Unactivated Alkyl Halides
-
The use of pyridine as the sole ligand for the reductive vinylation of unactivated secondary alkyl halides under Ni-catalyzed conditions has been developed. Both alkyl- and aryl-substituted vinyl bromides are suitable, in which alkyl-decorated α-alkenyl bromides resulted in the α-products in good results.
- Gu, Jun,Qiu, Canbin,Lu, Wenbin,Qian, Qun,Lin, Kunhua,Gong, Hegui
-
supporting information
p. 1867 - 1873
(2017/04/06)
-
- Direct Alkynylation of 3H-Imidazo[4,5-b]pyridines Using gem-Dibromoalkenes as Alkynes Source
-
C2 direct alkynylation of 3H-imidazo[4,5-b]pyridine derivatives is explored for the first time. Stable and readily available 1,1-dibromo-1-alkenes, electrophilic alkyne precursors, are used as coupling partners. The simple reaction conditions include an inexpensive copper catalyst (CuBr·SMe2 or Cu(OAc)2), a phosphine ligand (DPEphos) and a base (LiOtBu) in 1,4-dioxane at 120 °C. This C-H alkynylation method revealed to be compatible with a variety of substitutions on both coupling partners: heteroarenes and gem-dibromoalkenes. This protocol allows the straightforward synthesis of various 2-alkynyl-3H-imidazo[4,5-b]pyridines, a valuable scaffold in drug design.
- Aziz, Jessy,Baladi, Tom,Piguel, Sandrine
-
p. 4122 - 4133
(2016/06/09)
-
- 1,1-Dibromoalkenes as versatile reagents to a transition metal-free and stereoselective synthesis of (E)-1-bromo-1-selenoalkenes and ketene selenoacetals
-
We describe here a metal-free and selective method for the synthesis of (E)-1-bromo-1-seleno alkenes and ketene selenoacetals by a stoichiometric and temperature-controlled reaction. These protocols employ a diverse array of 1,1-dibromoalkenes and different diaryl diselenides to afford the corresponding products in good yields and in a short reaction time.
- Webber, Rodrigo,Peglow, Thiago J.,Nobre, Patrick C.,Barcellos, Angelita M.,Roehrs, Juliano A.,Schumacher, Ricardo F.,Perin, Gelson
-
supporting information
p. 4128 - 4132
(2016/08/24)
-
- Preparation of Vinyl Arenes by Nickel-Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides
-
This work emphasizes the synthesis of substituted vinyl arenes by reductive coupling of aryl halides with vinyl bromides under mild and easy-to-operate nickel-catalyzed reaction conditions. A broad range of aryl halides, including heteroaromatics, and vinyl bromides were employed to yielding products in moderate to excellent yields with high functional-group tolerance. The nickel-catalytic system displays good chemoselectivity between the two C(sp2)-halide coupling partners, thus demonstrating a mechanistic pathway distinct from other stepwise protocols.
- Liu, Jiandong,Ren, Qinghua,Zhang, Xinghua,Gong, Hegui
-
supporting information
p. 15544 - 15548
(2016/12/09)
-
- Ionic liquids as a reusable media for copper catalysis. Green access to alkenes using catalytic olefination reaction
-
It was demonstrated that ionic liquids are superb recyclable media for copper catalyzed reactions using catalytic olefination reaction as an example. As a result a novel green access to the halogenoalkenes was elaborated. Possibility to perform up to five reaction cycles without catalyst leaching and decreasing of the yield was demonstrated. A number of various ionic liquids was screened and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim] [BF4]) was found the solvent with highest efficiency. Mild conditions, high atom economy comparing to other known methods, low amounts of wastes and possibility to recover ionic liquid are the advantages of the proposed method.
- Muzalevskiy, Vasily M.,Shastin, Aleksey V.,Shikhaliev, Namiq G.,Magerramov, Abel M.,Teymurova, Aytekin N.,Nenajdenko, Valentine G.
-
p. 7159 - 7163
(2016/10/24)
-
- Dual gold catalysis: A novel synthesis of bicyclic and tricyclic pyrroles from n -propargyl ynamides
-
Various N-propargyl ynamides were converted to bicylic and tricyclic pyrroles by the use of a cationic dual-activation gold catalyst. This reaction starts with the nucleophilic addition of a gold acetylide onto an ynamide triple bond at the ?2-position of the nitrogen atom. Thus, gold vinylidene is formed, and then a second cyclization takes place. The formation of the gold vinylidene is indicated by the evidence that not only aryl ynamides but also alkyl ynamides undergo C-H activation in these reactions.
- Tokimizu, Yusuke,Wieteck, Marcel,Rudolph, Matthias,Oishi, Shinya,Fujii, Nobutaka,Hashmi, A. Stephen K.,Ohno, Hiroaki
-
supporting information
p. 604 - 607
(2015/03/05)
-
- Copper-catalyzed N-alkynylations of sulfoximines with bromoacetylenes
-
N-Alkynylated sulfoximines have been obtained by copper-catalyzed cross-coupling reactions starting from NH-sulfoximines and bromoacetylenes in moderate to good yields. The reaction conditions are mild, and the substrate scope is wide.
- Chen, Xiao Yun,Wang, Long,Frings, Marcus,Bolm, Carsten
-
supporting information
p. 3796 - 3799
(2014/08/05)
-
- Gold-catalyzed 1,2-iminonitronation of electron-deficient alkynes with nitrosoarenes to afford α-imidoyl nitrones
-
Gold-catalyzed 1,2-iminonitronation of propiolate derivatives with nitrosoarenes to give α-imidoyl nitrones is described; this new reaction is applicable to diverse propiolate derivatives and nitrosoarenes.
- Singh, Rahulkumar Rajmani,Liu, Rai-Shung
-
supporting information
p. 15864 - 15866
(2015/01/08)
-
- Palladium(0)-catalyzed cross-coupling of 1,1-diboronates with vinyl bromides and 1,1-dibromoalkenes
-
Palladium-catalyzed cross-coupling reactions of 1,1-diboronates with vinyl bromides and dibromoalkenes were found to afford 1,4-dienes and allenes, respectively. These reactions utilize the high reactivities of both 1,1-diboronates and allylboron intermediates generated in the initial coupling.
- Li, Huan,Zhang, Zhikun,Shangguan, Xianghang,Huang, Shan,Chen, Jun,Zhang, Yan,Wang, Jianbo
-
supporting information
p. 11921 - 11925
(2015/01/09)
-
- Nickel(II)-magnesium-catalyzed cross-coupling of 1,1-dibromo-1-alkenes with diphenylphosphine oxide: One-pot synthesis of (E)-1-alkenylphosphine oxides or bisphosphine oxides
-
A novel nickel(II)-magnesium-mediated cross-coupling of diphenylphosphine oxide with a variety of 1,1-dibromo-1-alkenes has been developed, which provides a powerful and general methodology for the stereoselective synthesis of various (E)-1-alkenylphosphine oxides or bisphosphine oxides, with operational simplicity of the procedure, good to high yields and broad substrate applicability. Mechanistic studies reveal that the reaction might involve a Hirao reduction, cross-coupling and Michael addition. Copyright
- Liu, Liu,Wang, Yulei,Zeng, Zhiping,Xu, Pengxiang,Gao, Yuxing,Yin, Yingwu,Zhao, Yufen
-
supporting information
p. 659 - 666
(2013/04/10)
-
- Formation of quaternary stereogenic centers by copper-catalyzed asymmetric conjugate addition reactions of alkenylaluminums to trisubstituted enones
-
Alkenylaluminums undergo asymmetric copper-catalyzed conjugate addition (ACA) to β-substituted enones allowing the formation of stereogenic all-carbon quaternary centers. Phosphinamine-copper complexes proved to be particularly active and selective compared with phosphoramidite ligands. After extensive optimization, high enantioselectivities (up to 96 % ee) were obtained for the addition of alkenylalanes to β-substituted enones. Two strategies for the generation of the requisite alkenylaluminums were explored allowing for the introduction of aryl- and alkyl-substituted alkenyl nucleophiles. Moreover, alkyl-substituted phosphinamine (SimplePhos) ligands were identified for the first time as highly efficient ligands for the Cu-catalyzed ACA. Chiral synthesis made easy: The copper-catalyzed conjugate addition of alkenylaluminum reagents to 3-substituted cyclic enones allows for the formation of all-carbon chiral quaternary centers (see scheme; CuTC=copper(I) thiophene-2-carboxylate). Chiral phosphinamine (SimplePhos) ligands were found to be highly efficient for this transformation.
- Mueller, Daniel,Alexakis, Alexandre
-
supporting information
p. 15226 - 15239
(2013/11/06)
-
- An efficient one-pot synthesis of 3,5-diaryl-4-bromopyrazoles by 1,3-dipolar cycloaddition of in situ generated diazo compounds and 1-bromoalk-1-ynes
-
A simple, highly efficient, one-pot synthesis of 3,5-di-aryl-4- bromopyrazoles via 1,3-dipolar cycloaddition of diazo compounds and alkynyl bromides has been developed. The diazo compounds and alkynyl bromides were generated in situ from tosylhydrazones and gem-dibromoalkenes, respectively. When ketone-derived hydrazones were used, 3,5-diaryl-4-bromo-3H-pyrazoles were obtained and the isomerization products 3,5-diaryl-4-bromo-1H-pyrazoles were formed when using aldehyde-derived hydrazones. The reaction system exhibited high regioselectivity and good functional group tolerance. Both electron-rich and electron-deficient-substituents on the aromatic ring of the hydrazones or the gem-dibromoalkenes gave desired products in moderate to good yields (67-86%). Georg Thieme Verlag Stuttgart - New York.
- Sha, Qiang,Wei, Yunyang
-
supporting information
p. 413 - 420
(2013/03/14)
-
- Copper catalyzed decarboxylative alkynylation of quaternary α-cyano acetate salts
-
Cu-catalyzed decarboxylative alkynylation of quaternary α-cyano acetate salts with alkynyl bromides and alkynyl chlorides is described. This new reaction can be used for preparing functionalized butynenitrile derivatives.
- Feng, Yi-Si,Xu, Zhong-Qiu,Mao, Long,Zhang, Feng-Feng,Xu, Hua-Jian
-
supporting information
p. 1472 - 1475
(2013/06/27)
-
- N-heterocyclic carbene-catalyzed annulation of α-cyano-1,4-diketones with ynals
-
In this paper, the first stereoselective annulation reaction between r-cyano-1,4-diketones and ynals, mediated by catalytic amounts of a triazolium salt precatalyst and cocatalytic amounts of a weak carboxylate base, is disclosed. The title transformation proceeds smoothly under mild reaction conditions and generates three contiguous stereogenic centers, one of which is a quaternary acetal carbon. This reaction tolerates a wide variety of electronically distinct substituents on both reaction partners and affords privileged bicyclic scaffolds in 61-90% isolated yields and with up to 20:1 diastereomeric preference.
- Romanov-Michailidis, Fedor,Besnard, Celine,Alexakis, Alexandre
-
supporting information
p. 4906 - 4909,4
(2012/12/12)
-
- N-heterocyclic carbene-catalyzed annulation of α-cyano-1,4-diketones with ynals
-
In this paper, the first stereoselective annulation reaction between r-cyano-1,4-diketones and ynals, mediated by catalytic amounts of a triazolium salt precatalyst and cocatalytic amounts of a weak carboxylate base, is disclosed. The title transformation proceeds smoothly under mild reaction conditions and generates three contiguous stereogenic centers, one of which is a quaternary acetal carbon. This reaction tolerates a wide variety of electronically distinct substituents on both reaction partners and affords privileged bicyclic scaffolds in 61-90% isolated yields and with up to 20:1 diastereomeric preference.
- Romanov-Michailidis, Fedor,Besnard, Céline,Alexakis, Alexandre
-
supporting information
p. 4906 - 4909
(2013/01/15)
-
- Copper-mediated C-H activation of 1,3,4-oxadiazoles with 1,1-dibromo-1-alkenes using PEG-400 as a solvent medium: Distinct approach for the alkynylation of 1,3,4-oxadiazoles
-
The direct C-H alkynylation of 1,3,4-oxadiazoles with 1,1-dibromo-1-alkenes has been accomplished by using a combination of CuBr/LiOtBu in PEG-400 (a green solvent) at 80 °C. The products were formed in high yields (73-86%) in 2 h. No additional ligand or volatile solvent was required and the conversion was ecofriendly. The direct C-H alkynylation of 1,3,4-oxadiazoles with 1,1-dibromo-1-alkenes has been accomplished by using a combination of CuBr/LiOtBu in PEG-400 (a green solvent) at 80 °C. The products were formed in high yields (73-86%) in 2 h. No additional ligand or volatile solvent was required and the conversion was ecofriendly. Copyright
- Reddy, Gandolla Chinna,Balasubramanyam, Penagaluri,Salvanna,Das, Biswanath
-
supporting information; experimental part
p. 471 - 474
(2012/03/08)
-
- Pd-Catalyzed C-3 functionalization of indolizines via C-H bond cleavage
-
New transition metal-catalyzed methods for the arylation of indolizines by the direct cleavage of C-H bonds have been developed. A wide range of aryltrifluoroborate salts react with indolizines in the presence of Pd(OAc) 2 catalyst and AgOAc oxidant to give the arylated indolizines in high yields. Both electron-donating and electron-withdrawing groups perform smoothly while bromide and chlorine substituents are tolerated. In addition, the indolizines display similar reactivities in the Pd-catalyzed reaction with 3-phenylpropiolic acid to afford the corresponding C-3 alkynylated indolizines. These methods allow the direct functionalization of indolizines in one step.
- Zhao, Baoli
-
supporting information; experimental part
p. 7108 - 7119
(2012/09/25)
-
- Synthesis of 1,2-disubstituted acetylenes via copper-catalyzed Suzuki coupling of organoboronic acids with 1,1-dibromo-1-alkenes
-
An efficient synthesis of 1,2-disubstituted acetylenes has been described. Reactions of organoboronic acids with 1,1-dibromo-1-alkenes in the presence of a catalytic amount of CuI (10 mol %), 8-hydroxyquinoline (10 mol %), and using potassium phosphate as base in C2H5OH afforded the desired 1,2-disubstituted acetylenes in good to excellent yields. It is important to note that the formation of 1,3-diynes, which are derived from the homocoupling of 1,1-dibromo-1-alkenes, can be almost completely suppressed under these optimized conditions.
- Liu, Jidan,Dai, Fenglin,Yang, Zhiyong,Wang, Sizhuo,Xie, Kai,Wang, Anwei,Chen, Xiang,Tan, Ze
-
supporting information
p. 5678 - 5683
(2015/04/15)
-
- Functionalisation of heteroaromatic N-oxides using organic superbase catalyst
-
Functionalisation of quinoline N-oxide was investigated using phophazene base as a catalyst; alkynylation and heteroarylation at 2-position were successfully achieved via nucleophilic addition-elimination process.
- Araki, Yuta,Kobayashi, Koji,Yonemoto, Misato,Kondo, Yoshinori
-
supporting information; experimental part
p. 78 - 80
(2011/02/23)
-
- Convenient synthesis of 2-aryl-1-haloindolizines from pyridinium salts and 2-aryl-1,1-dihaloalk-1-enes
-
2-Aryl-1-haloindolizines were synthesized from pyridinium salts and 2-aryl-1,1-dihaloalk-1-enes using a DBU/THF system. 2-Aryl-1,1-dihaloalk-1-enes containing electron-withdrawing or -donating groups were efficiently converted into the corresponding 2-aryl-1-haloindolizines in moderate to excellent yields. Georg Thieme Verlag Stuttgart.
- Yang, Yiwen,Kuang, Chunxiang,Jin, Hui,Yang, Qing
-
supporting information; experimental part
p. 3447 - 3452
(2011/12/04)
-
- Palladium-catalyzed tandem amination reaction for the synthesis of 4-quinolones
-
(Figure presented) An efficient palladium-catalyzed tandem amlnatlon approach was developed In one step to afford functlonallzed 4-qulnolones In good to excellent ylelds from easlly accessible o-haloaryl acetylenlc ketones and primary amines.
- Zhao, Tlankun,Xu, Bin
-
supporting information; experimental part
p. 212 - 215
(2010/03/24)
-
- Pd-catalyzed domino synthesis of internal alkynes using triarylbismuths as multicoupling organometallic nucleophiles
-
Figure presented The domino coupling reaction of 1,1-dibromo-1-alkenes with triarylbismuth nucleophiles has been demonstrated to furnish disubstituted alkynes directly under catalytic palladium conditions. The couplings of triarylbismuths as multicoupling nucleophiles with 3 equiv of 1,1-dibromo-1-alkenes are very fast, affording high yields of alkynes in a short reaction time. Thus, an efficient domino process has been accomplished using 1,1-dibromo-1-alkenes as surrogates for internal alkyne synthesis in couplings with triarylbismuths in a one-pot operation.
- Rao, Maddali L. N.,Jadhav, Deepak N.,Dasgupta, Priyabrata
-
supporting information; experimental part
p. 2048 - 2051
(2010/07/03)
-
- A short route to [1,2,3]-triazolyl coumarin and quinolone derivatives by Cu(I) catalyzed 1,3-dipolar cycloaddition and fluorescence studies
-
Hitherto unreported [1,2,3]-triazolyl coumarin and quinolone derivatives in good to excellent yields have been expediently synthesized from 6- and 7-azidocoumarin and 6-azidoquinolone by copper (I) catalyzed 1,3-dipolar cycloaddition. Azidocoumarins and a
- Majumdar, Krishna C.,Mondal, Shovan
-
experimental part
p. 82 - 87
(2010/04/23)
-
- Structure-activity relationship study of a novel necroptosis inhibitor, necrostatin-7
-
Necroptosis is a regulated caspase-independent cell death mechanism characterized by morphological features resembling non-regulated necrosis. Necrotatin-7 (Nec-7), a novel potent small-molecule inhibitor of necroptosis, is structurally distinct from previously described necrostatins (Nec-1, Nec-3, Nec-4 and Nec-5). Here, we describe a series of structural modifications and the structure-activity relationship (SAR) of the Nec-7 series for inhibiting necroptosis.
- Zheng, Weihong,Degterev, Alexei,Hsu, Emily,Yuan, Junying,Yuan, Chengye
-
scheme or table
p. 4932 - 4935
(2009/05/26)
-
- Effect of the catalyst nature and quantity on catalytic olefination
-
The study of the catalyst nature effect on the catalytic olefination of 4-chlorobenzaldehyde hydrazone by polyhaloalkanes revealed that the best catalysts for the reaction are copper salts. With polyhaloalkanes more active than CCl4, like CBrs
- Shastin,Muzalevskii,Korotchenko,Balenkova,Nenaidenko
-
p. 183 - 189
(2007/10/03)
-
- Rhodium-catalyzed regio- and enantioselective intermolecular [4+2] carbocyclization of 4-alkynals with N,N-dialkyl acrylamides
-
(Chemical Equation Presented) Selective rings: A cationic Rh I-(R,R)-walphos complex catalyzes a highly regio-and enantioselective intermolecular [4+2] carbocyclization of 4-alkynals with N,N-dialkyl acrylamides to afford enantioenriched cyclohexanones (see scheme; cod = cycloocta-1,5-diene). This new route is attractive in view of the one-step access to 4-alkynals from commercially available reagents.
- Tanaka, Ken,Hagiwara, Yuji,Noguchi, Keiichi
-
p. 7260 - 7263
(2007/10/03)
-
- Diamine derivatives
-
A compound represented by the general formula (1): Q1-Q2-T0-N(R1)-Q3-N(R2)-T1-Q4??(1) wherein R1 and R2 are hydrogen atoms or the like; Q1 is a saturated or unsaturated, 5- or 6-membered cyclic hydrocarbon group which may be substituted, or the like; Q2 is a single bond or the like; Q3 is a group in which Q5 is an alkylene group having 1 to 8 carbon atoms, or the like; and T0 and T1 are carbonyl groups or the like; a salt thereof, a solvate thereof, or an N-oxide thereof. The compound is useful as an agent for preventing and/or treating cerebral infarction, cerebral embolism, myocardial infarction, angina pectoris, pulmonary infarction, pulmonary embolism, Buerger's disease, deep venous thrombosis, disseminated intravascular coagulation syndrome, thrombus formation after valve or joint replacement, thrombus formation and reocclusion after angioplasty, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), thrombus formation during extracorporeal circulation, or blood clotting upon blood drawing.
- -
-
-
- DIAMINE DERIVATIVES
-
A compound represented by formula (1):Q1-Q2-To-N(R1) -Q3-N(R2)-T1-Q4 [wherein R1 and R2 are hydrogen atoms or the like; Q1 is a saturated or unsaturated, 5- or 6- membered cyclic hydrocarbon group which may be substituted, or the like; Q2 is a single bond or the like; Q3 represents the following group: (wherein Q5 is an alkylene group having 1 to 8 carbon atoms, or the like); and T0 and T1 are carbonyl groups or the like], a salt thereof, a solvate thereof, or an N-oxide thereof. The compound is useful as an agent for preventing and/or treating cerebral infarction, cerebral embolism, myocardial infarction, angina pectoris, pulmonary infarction, pulmonary embolism, Buerger's disease, deep venous thrombosis, disseminated intravascular coagulation syndrome, thrombus formation after artificial valve or joint replacement, thrombus formation and reocclusion after angioplasty, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), thrombus formation during extracorporeal circulation, or blood clotting upon blood drawing.
- -
-
Page/Page column 242
(2008/06/13)
-
- DIAMINE DERIVATIVES
-
A compound represented by the general formula (1):Q1-Q2-T0-N(R1)-Q3-N(R2)-T1-Q4 wherein R1 and R2 are hydrogen atoms or the like; Q1 is a saturated or unsaturated, 5- or 6- membered cyclic hydrocarbon group which may be substituted, or the like; Q2 is a single bond or the like; Q3 is a group in which Q5 is an alkylene group having 1 to 8 carbon atoms, or the like; and T0 and T1 are carbonyl groups or the like; a salt thereof, a solvate thereof, or an N-oxide thereof. The compound is useful as an agent for preventing and/or treating cerebral infarction, cerebral embolism, myocardial infarction, angina pectoris, pulmonary infarction, pulmonary embolism, Buerger's disease, deep venous thrombosis, disseminated intravascular coagulation syndrome, thrombus formation after valve or joint replacement, thrombus formation and reocclusion after angioplasty, systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), thrombus formation during extracorporeal circulation, or blood clotting upon blood drawing.
- -
-
-