- Allenylidene Induced 1,2-Metalate Rearrangement of Indole-Boronates: Diastereoselective Access to Highly Substituted Indolines
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A process to achieve 1,2-metalate rearrangements of indole boronate as a way to access substituted indolines in high diastereoselectivities is presented. The reaction involves the generation of a Cu–allenylidene, which is sufficiently electrophilic to induce the 1,2-metalate rearrangement. The scope of the reaction is evaluated as well as further transformations of the product.
- Simlandy, Amit Kumar,Brown, M. Kevin
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- Enantioselective Propargylation of Polyols and Desymmetrization of meso 1,2-Diols by Copper/Borinic Acid Dual Catalysis
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A copper/borinic acid dual catalytic reaction enabled the enantioselective propargylation of aliphatic polyols. Readily available reagents and catalysts were used in this transformation, which displayed good to excellent chemo- and stereoselectivity for a broad array of substrates. The method was also applicable to the desymmetrization of meso 1,2-diols to furnish products with three stereogenic centers and a terminal alkyne group in one operation.
- Li, Ren-Zhe,Tang, Hua,Yang, Ke R.,Wan, Li-Qiang,Zhang, Xia,Liu, Jie,Fu, Zhengyan,Niu, Dawen
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- Photoinitiated anti-Hydropentafluorosulfanylation of Terminal Alkynes
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A photoinitiated anti-hydropentafluorosulfanylation of terminal alkynes using SF5Cl and (TMS)3SiH as the hydrogen atom donor is reported. This transformation generates selectively (Z)-(1-alken-1-yl)pentafluoro-λ6-sulfanes
- Birepinte, Mélodie,Champagne, Pier Alexandre,Paquin, Jean-Fran?ois
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supporting information
(2021/11/30)
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- Multisubstituted pyrazole synthesis via [3?+?2] cycloaddition/rearrangement/N[sbnd]H insertion cascade reaction of α-diazoesters and ynones
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The cascade reactions of alkyl α-diazoesters and ynones using Al(OTf)3 as the catalyst are described. A series of 4-substituted pyrazoles were obtained via [3 + 2] cycloaddition, 1,5-ester shift, 1,3-H shift, and N[sbnd]H insertion process. Deuterium labelling experiments, kinetic studies and control experiments were carried out for the rationalization of the mechanism.
- Feng, Xiaoming,Liu, Xiaohua,Zeng, Zi,Zhao, Peng
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supporting information
p. 132 - 135
(2020/12/21)
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- Palladium-catalyzed [3+2] annulation of allenyl carbinol acetates with C,N-cyclic azomethine imines
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In this paper, a palladium-catalyzed [3+2] annulation of allenyl carbinol acetates with azomethine imines has successfully been developed under mild reaction conditions, affording biologically interesting tetrahydropyrazoloisoquinoline derivatives in high to excellent yields and with excellent stereoselectivity. The reaction follows a tandem [3+2] cycloaddition/allylation/elimination of AcOH pathway. Allenyl carbinol acetates also reacted well with in situ generated azomethine imine under cocatalysis of Ag(i)/Pd(0) catalysts in a similar reaction pathway.
- Mao, Biming,Zhang, Junya,Xu, Yi,Yan, Zhengyang,Wang, Wei,Wu, Yongjun,Sun, Changqing,Zheng, Bing,Guo, Hongchao
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supporting information
p. 12841 - 12844
(2019/11/05)
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- Phosphorous acid promoted isomerization of propargyl alcohols to α,β-unsaturated carbonyl compounds
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A metal-free and two-phase protocol for the Meyer-Schuster isomerization of propargyl alcohols to the corresponding α,β-unsaturated carbonyl compounds has been achieved in the presence of stoichiometric phosphorous acid aqueous solution, which produces the desired products in high yields with excellent stereoselectivity. Compared with the traditional methods, the procedure features broad scope of the substrates, mild conditions, and easy separation, providing an appealing alternative to the Meyer-Schuster reaction.
- Gan, Xiaotang,Fu, Zuqi,Liu,Yan, Yani,Chen, Chao,Zhou, Yongbo,Dong, Jianyu
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supporting information
(2019/07/12)
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- One-Pot, Three-Step Synthesis of Cyclopropylboronic Acid Pinacol Esters from Synthetically Tractable Propargylic Silyl Ethers
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Simple propargylic silyl ethers can be converted to complex cyclopropylboronic acid pinacol esters in an efficient one-pot procedure. Terminal acetylenes undergo a Schwartz's reagent catalyzed hydroboration; subsequent addition of further Schwartz's reage
- Spencer, Jonathan A.,Jamieson, Craig,Talbot, Eric P. A.
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supporting information
p. 3891 - 3894
(2017/07/26)
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- Synthesis of Vinyl-, Allyl-, and 2-Boryl Allylboronates via a Highly Selective Copper-Catalyzed Borylation of Propargylic Alcohols
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An efficient methodology for the synthesis of vinyl-, allyl-, and (E)-2-boryl allylboronates from propargylic alcohols via Cu-catalyzed borylation under mild conditions is reported. In the presence of commercially available Cu(OAc)2 or Cu(acac)2 and Xantphos, the reaction affords the desired products in up to 92% yield with a broad substrate scope (43 examples). Isolation of an allenyl boronate as the reaction intermediate suggests that an insertion-elimination-type reaction, followed by borylcupration, is involved in the borylation of propargylic alcohols.
- Mao, Lujia,Bertermann, Rüdiger,Emmert, Katharina,Szabó, Kálmán J.,Marder, Todd B.
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supporting information
p. 6586 - 6589
(2017/12/26)
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- Well-Defined Chiral Gold(III) Complex Catalyzed Direct Enantioconvergent Kinetic Resolution of 1,5-Enynes
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The development of a gold(III) catalyzed direct enantioconvergent 1,5-enyne cycloisomerization and kinetic resolution reaction is described. The transformation results in highly enantioenriched bicyclo[3.1.0]hexenes at all levels of conversion, with no racemization or symmetrization taking place during the course of the reaction, and simultaneously affords optically enriched 1,5-enynes. This report marks the first highly enantioselective transformation catalyzed by a well-defined cationic gold(III) catalyst and demonstrates the unique potential of gold(III) complexes in enantioselective catalysis.
- Bohan, Patrick T.,Dean Toste
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supporting information
p. 11016 - 11019
(2017/08/22)
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- Styrene as 4π-Component in Zn(II)-Catalyzed Intermolecular Diels-Alder/Ene Tandem Reaction
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A mild Zn-catalyzed intermolecular Diels-Alder/ene tandem reaction with styrene as a 4π-component is reported. A variety of dihydronaphthalene products could be prepared in moderate to good yields. Moreover, a combination of DFT calculations and experiments was performed to further understand the mechanism of this unique tandem reaction.
- Zheng, Min,Wu, Feng,Chen, Kai,Zhu, Shifa
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supporting information
p. 3554 - 3557
(2016/08/16)
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- Cooperative catalysis: Enantioselective propargylic alkylation of propargylic alcohols with enecarbamates using ruthenium/Phosphoramide hybrid catalysts
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The diastereo- and enantioselective propargylic alkylation of propargylic alcohols with E-enecarbamates in the presence of a catalytic amount of thiolate-bridged diruthenium complexes bearing an optically active phosphoramide moiety gives the corresponding propargylic alkylated products (up to 97 % ee).
- Senda, Yasushi,Nakajima, Kazunari,Nishibayashi, Yoshiaki
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supporting information
p. 4060 - 4064
(2015/03/30)
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- Synthesis of β-Trifluoromethylated Ketones from Propargylic Alcohols by Visible Light Photoredox Catalysis
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Regioselective trifluoromethylation at a remote position represents an important challenge in the development of biologically active molecules and functional materials. A practical method to access β-trifluoromethyl ketones from readily available propargylic alcohols by visible light photocatalysis has been developed. Trifluoromethylation of propargylic alcohols with CF3I in the presence of Ru(bpy)3Cl2 as the photocatalyst followed by double-bond migration/keto-enol tautomerization provides β-trifluoromethyl ketones as the final product. β-Trifluoromethyl ketones are synthesized from readily available propargylic alcohols by visible light photocatalysis. Trifluoromethylation followed by double-bond migration/keto-enol tautomerization provides β-trifluoromethyl ketones as the final product.
- Park, Sehyun,Joo, Jung Min,Cho, Eun Jin
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supporting information
p. 4093 - 4097
(2015/07/01)
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- Stereoselective, Cascade Synthesis of trans-Enynones through Coupling-Isomerization Reaction
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A mild, cascade methodology based on the modified Cadiot-Chodkiewicz reaction was developed for the stereoselective synthesis of trans-enynones. By this methodology, structurally divergent trans-enynones, which are embedded with sensitive functional groups, were synthesized. Control experiments suggested that the CuCl alone does not have a role in the isomerization step, whereas the CuCl-piperidine complex (formed during the cross coupling) may have a rate enhancing effect. Furthermore, additional sets of control experiments favor the involvement of unimolecular [1,2]-H shift rather than a homobimolecular proton abstraction during the isomerization step.
- Chinta, Bhavani Shankar,Baire, Beeraiah
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p. 10208 - 10217
(2015/11/03)
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- Bronsted acid mediated nitrogenation of propargylic alcohols: An efficient approach to alkenyl nitriles
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A novel and efficient approach to alkenyl nitriles from readily available propargylic alcohols has been developed. This nitrogenation reaction is transition-metal-free and could be conducted under air at ambient temperature, which makes this protocol promising and practical. Moreover, NH4Br is disclosed as an efficient additive to promote the stereoselectivity of this reaction. the Partner Organisations 2014.
- Huang, Xiaoqiang,Jiao, Ning
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supporting information
p. 4324 - 4328
(2014/06/23)
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- Direct synthesis of pyrroles via 1,3-dipolar cycloaddition of azomethine ylides with ynones
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A direct and facile synthesis of multi-substituted pyrroles via AgOAc-catalyzed 1,3-dipolar cycloaddition of azomethine ylides with ynones is developed, providing the corresponding adducts in moderate to high yields (up to 89%).
- Wang, Zheng,Shi, Ying,Luo, Xiaoyan,Han, De-Man,Deng, Wei-Ping
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supporting information
p. 1742 - 1745
(2013/06/27)
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- 1-Phenyl-4-benzoyl-1H-1,2,3-triazoles as orally bioavailable transcriptional function suppressors of Estrogen-related receptor α
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Estrogen-related receptor α is a potential candidate target for therapeutic treatment of breast cancer. We describe the discovery and structure-activity relationship study of a series of 1-phenyl-4-benzoyl-1H-1,2, 3-triazoles as novel suppressors of ERRα
- Xu, Shilin,Zhuang, Xiaoxi,Pan, Xiaofen,Zhang, Zhang,Duan, Lei,Liu, Yingxue,Zhang, Lianwen,Ren, Xiaomei,Ding, Ke
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p. 4631 - 4640
(2013/07/19)
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- Silver(I)-catalyzed reaction between pyrazole and propargyl acetates: Stereoselective synthesis of the scorpionate ligands (E)-allyl-gem-dipyrazoles (ADPs)
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The reaction between readily accessible pyrazole and propargyl acetates in the presence of Ag(I) catalyst yielded a new class of (E)-allyl-gem-dipyrazole scorpionate ligands: 1-aryl-2-N-pyrazolyl allyl acetates and 1,3-dipyrazolyl-3-arylpropene. The reaction showed broad substrate scope, and various functional and protecting groups were tolerated under the reaction conditions. The palladium(II) scorpionate complex could thus be easily prepared and successfully employed in Suzuki-Miyaura cross-couplings in water.
- Bhanuchandra,Kuram, Malleswara Rao,Sahoo, Akhila K.
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p. 11824 - 11834
(2014/01/06)
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- Chiral silver phosphate-catalyzed cycloisomeric kinetic resolution of α-allenic alcohols
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A kinetic resolution of α-allenic alcohols is realized through chiral silver phosphate-catalyzed cycloisomerization with high stereoselectivity (selectivity factor up to 189) and tolerance of a variety of functional groups. A mechanistic model is proposed to interpret the origin of the high stereoselectivity and broad substrate scope.
- Wang, Yan,Zheng, Kuan,Hong, Ran
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supporting information; scheme or table
p. 4096 - 4099
(2012/04/10)
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- Palladacycle-catalyzed reaction of bicyclic alkenes with terminal ynones: Regiospecific synthesis of polysubstituted furans
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A new synthetic strategy to access polysubstituted furans regiospecifically has been developed using simple bicyclic alkenes and terminal ynones as starting materials with palladacycles as unique active catalysts. A rational mechanism has also been proposed. This reaction features mild reaction conditions, easily available starting materials and palladacycle catalysts, a wide substrate scope, and high regiospecificity.
- Ge, Guang-Cun,Mo, Dong-Liang,Ding, Chang-Hua,Dai, Li-Xin,Hou, Xue-Long
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supporting information
p. 5756 - 5759
(2013/01/15)
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- Iron(III) chloride-promoted isomerization of propargyl alcohols to α,β-unsaturated carbonyl compounds
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Aryl propargyl alcohols bearing a terminal alkynyl moiety can undergo a facile iron(III) chloride-promoted transformation to the corresponding α,β-unsaturated aldehyde in good yield and excellent stereoselectivity.
- El Douhaibi, Ahmad Samih,Judeh, Zaher M. A.,Basri, Hedaya,Moussa, Ziad,Messali, Mouslim,Qi, Gao
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scheme or table
p. 533 - 540
(2011/04/22)
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- Gold-catalyzed regioselective hydration of propargyl acetates assisted by a neighboring carbonyl group: Access to α-acyloxy methyl ketones and synthesis of (±)-actinopolymorphol B
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A general atom-economical approach for the synthesis of α-acyloxy methyl ketone is demonstrated through regioselective hydration of a wide range of propargyl acetates. Readily available catalyst comprising of 1% Ph 3PAuCl and 1% AgSbF6 in dioxane-H2O efficiently hydrolyzes the terminal alkynes of the propargyl acetate in the absence of acid promoters at ambient temperature within a short time. Effective regioselective hydration is facilitated by the neighboring carbonyl group as demonstrated through 18O-labeling study. Compatibility of functional moieties and tolerance to various acid-labile protecting groups are observed. The catalytic condition is also suitable to perform hydration of TMS-substituted propargyl acetates, even though it requires prolonged reaction time for completion. Stereointegrity of the propargylic acetate is preserved during the hydration. The robustness of the system is successfully demonstrated through gram scale preparation of the product in nearly quantitative yield. The common α-acyloxy methyl ketone is transformed to 1,2-diol and 1,2-amino alcohol derivatives. Synthesis of actinopolymorphol B is achieved for the first time involving hydration of the propargyl acetate as the key step.
- Ghosh, Nayan,Nayak, Sanatan,Sahoo, Akhila K.
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supporting information; experimental part
p. 500 - 511
(2011/04/17)
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- Base-catalyzed cascade 1,3-H shift/cyclization reaction to construct polyaromatic furans
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A convenient new method was developed to prepare unfused polyaromatic furan derivatives from diynyl-1,6-diols through a novel base-catalyzed cascade 1,3-H shift/cyclization process. Deuterium experiments were performed to determine that the 1,3-H shift was the rate-determining step. Copyright
- Wang, Ya-Hui,Liu, Heng,Zhu, Li-Li,Li, Xiao-Xiao,Chen, Zili
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supporting information; experimental part
p. 707 - 712
(2011/05/06)
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- Copper-catalyzed enantioselective propargylic amination of propargylic esters with amines: Copper-allenylidene complexes as key intermediates
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The scope and limitations of the copper-catalyzed propargylic amination of various propargylic esters with amines are presented, where optically active diphosphines such as Cl-MeO-BIPHEP and BINAP work as good chiral ligands. A variety of secondary amines are available as nucleophiles for this catalytic reaction to give the corresponding propargylic amines with a high enantioselectivity. The results of some stoichiometric and catalytic reactions indicate that the catalytic amination proceeds via copper-allenylidene complexes formed in situ, where the attack of amines to the electrophilic γ-carbon atom in the allenylidene complex is an important step for the stereoselection. Investigation of the relative rate constants for the reaction of several para-substituted propargylic acetates with N-methylanilines reveals that the formation of the copper-allenylidene complexes is involved in the rate-determining step. The result of the density functional theory calculation on a model reaction also supports the proposed reaction pathway involving copper-allenylidene complexes as key intermediates. The catalytic procedure presented here provides a versatile and direct method for the preparation of a variety of chiral propargylic amines.
- Hattori, Gaku,Sakata, Ken,Matsuzawa, Hiroshi,Tanabe, Yoshiaki,Miyake, Yoshihiro,Nishibayashi, Yoshiaki
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supporting information; experimental part
p. 10592 - 10608
(2010/09/10)
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- Remarkable high-yielding chemical modification of gold nanoparticles using uncatalyzed click-type i ,3-dipolar cycloaddition chemistry and hyperbaric conditions
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Azide-terminated alkyl thiolate monolayer-protected gold nanoparticles (1-C,12MPN) with a core size of 1.8 ± 0.2 nm were prepared. 1-C,12MPN was modified in high yields via an uncatalyzed 1,3-dipolar cycloaddition (clicktype reaction) with a variety of terminal acyl alkynes under hyperbaric conditions at 11 000 atm. The resulting 1,2,3-tria- zole modified MPNs (2-C,12MPN) were characterized using 1H NMR spectroscopy and were verified by comparison of the spectra to those obtained for the products of the model reactions of 1-azidododecane with the same alkynes. TEM analysis showed that the high-pressure conditions did not affect the size of the gold core, suggesting that the only effect is to facilitate the chemical reaction on the particles.
- Ismaili, Hossein,Alizadeh, Abdoihamid,Snell, Kristen E.,Workentin, Mark S.
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experimental part
p. 1708 - 1715
(2010/01/29)
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- Ruthenium-catalyzed enantioselective propargylation of aromatic compounds with propargylic alcohols via allenylidene intermediates
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(Chemical Equation Presented) High enantioselectivity was achieved in the Ru-catalyzed propargylation of furans and N,N-dimethylaniline derivatives to afford the propargylated aromatic compounds. This first asymmetric propargylation of aromatic compounds
- Matsuzawa, Hiroshi,Miyake, Yoshihiro,Nishibayashi, Yoshiaki
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p. 6488 - 6491
(2008/09/16)
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- Asymmetric dihydroxylation of allenes
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We have used asymmetric dihydroxylation (AD) of allenes in order to synthesize chiral α-hydroxy ketones. This methodology has been applied to several aryl-substituted allenes. We have found that electron donating groups on the aromatic ring increase the efficiency of the reaction.
- Fleming, Steven A.,Carroll, Sean M.,Hirschi, Jennifer,Liu, Renmao,Pace, J. Lee,Redd, J. Ty
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p. 3341 - 3343
(2007/10/03)
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- Ortho-[2,3]-wittig rearrangement of benzyl propargyl ethers: Striking preference over the competing [1,2]-wittig shift
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Treatment of benzyl γ-(trimethylsilyl)propargyl ether with n-BuLi is shown to afford the rarely precedent ortho-[2,3]-Wittig product in remarkable preference to the [1,2]-Wittig product. The factors governing the periselectivity in this type of carbanion
- Tomooka, Katsuhiko,Harada, Manabu,Hanji, Takayuki,Nakai, Takeshi
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p. 1394 - 1395
(2007/10/03)
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- Aryl propargylic alcohols of high enantiomeric purity via lipase catalyzed resolutions
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A variety of substituted aryl propargylic alcohols were prepared via lipase catalyzed resolutions, the enantioselective hydrolysis of the corresponding esters being the method of choice.
- Waldinger, Claudia,Schneider, Manfred,Botta, Maurizio,Corelli, Federico,Summa, Vincenzo
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p. 1485 - 1488
(2007/10/03)
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- Stereoselective alkynylation of chiral benzaldehyde chromium tricarbonyl complexes. Synthesis of optically active alkynyl alcohols
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Addition of lithium acetylides and ethynyl magnesium bromide to chiral ortho substituted benzaldehyde tricarbonylchromium complexes 1-3 gives alkynyl alcohols 4-7 in good yields and with complete stereoselection.
- Baldoli, Clara,Del Buttero, Paola,Licandro, Emanuela,Maiorana, Stefano,Papagni, Antonio,Torchio, Maurizio
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p. 7943 - 7946
(2007/10/02)
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