191403-23-3Relevant academic research and scientific papers
Selective Insertion of Alkynes into C-C σ Bonds of Indolin-2-ones: Transition-Metal-Free Ring Expansion Reactions to Seven-Membered-Ring Benzolactams or Chromone Derivatives
Wang, Mengdan,Yang, Yajie,Song, Bo,Yin, Liqiang,Yan, Shuhui,Li, Yanzhong
supporting information, p. 155 - 159 (2020/01/03)
An unprecedented ring expansion reaction of indolin-2-ones with alkynyl ketones under transition-metal-free conditions has been developed. Base-promoted selective cleavage of a C-C σ bond of the amide is the key in this process, which provides a straightf
Access to 2-Alkyl/Aryl-4-(1 H)-Quinolones via Orthogonal "nH3" Insertion into o-Haloaryl Ynones: Total Synthesis of Bioactive Pseudanes, Graveoline, Graveolinine, and Waltherione F
Mehta, Goverdhan,Nerella, Sharanya,Pabbaraja, Srihari,Singh, Shweta
supporting information, (2020/02/22)
An efficient one-pot synthesis of 4-(1H)-quinolones through an orthogonal engagement of diverse o-haloaryl ynones with ammonia in the presence of Cu(I), involving tandem Michael addition and ArCsp2-N coupling, is presented. The substrate scope of this convenient protocol, wherein ammonium carbonate acts as both an in situ ammonia source and a base toward diverse 2-substituted 4-(1H)-quinolones, has been mapped and its efficacy validated through concise total synthesis of bioactive natural products pseudanes (IV, VII, VIII, and XII), graveoline, graveolinine, and waltherione F.
Combining Electronic and Steric Effects to Generate Hindered Propargylic Alcohols in High Enantiomeric Excess
Vyas, Vijyesh K.,Knighton, Richard C.,Bhanage, Bhalchandra M.,Wills, Martin
supporting information, p. 975 - 978 (2018/02/23)
Tethered ruthenium-TsDPEN complexes have been applied to the catalysis of the asymmetric transfer hydrogenation of a range of aryl/acetylenic ketones. The introduction of an ortho- substituent to the aryl ring of the substrate results in a reversal of the
Nitromethane as a Carbanion Source for Domino Benzoannulation with Ynones: One-Pot Synthesis of Polyfunctional Naphthalenes and a Total Synthesis of Macarpine
Singh, Shweta,Samineni, Ramesh,Pabbaraja, Srihari,Mehta, Goverdhan
supporting information, p. 16847 - 16851 (2018/11/27)
A one-pot, transition-metal-free, domino Michael/SNAr protocol of general applicability has been devised for the regioselective synthesis of polyfunctional naphthalenes by employing nitromethane and ortho-haloaryl ynones. Utilization of nitromethane as a one carbon carbanion source that is incorporated into a variety of ynones, ends up as an aromatic nitro substituent. The application of this domino process towards a total synthesis of the polycyclic alkaloid macarpine demonstrate for the efficacy of this methodology. The conceptually simple approach to affect regioselective, multifunctional benzoannulation of ynones displays wide substrate scope and functional-group tolerance and has been implemented with substituted nitromethanes, as well as with alicyclic o-haloynones.
Base-mediated insertion reaction of alkynes into carbon-carbon σ-bonds of ethanones: synthesis of hydroxydienone and chromone derivatives
Zhang, Fangfang,Yao, Qiyi,Yuan, Yang,Xu, Murong,Kong, Lingkai,Li, Yanzhong
supporting information, p. 2497 - 2500 (2017/04/03)
Transition-metal free insertions of alkynes into carbon-carbon σ-bonds of ethanones have been reported. These tandem reactions offer an efficient synthesis of hydroxydienones and multi-substituted chromones. This is the first example of base-promoted insertion reactions of isolated carbon-carbon triple bonds into carbon-carbon σ-bonds with active methylene compounds bearing only one electron-withdrawing group.
Enantioselective Alkynylation of Aromatic Aldehydes Catalyzed by a Sterically Highly Demanding Chiral-at-Rhodium Lewis Acid
Luo, Shipeng,Zhang, Xiao,Zheng, Yu,Harms, Klaus,Zhang, Lilu,Meggers, Eric
, p. 8995 - 9005 (2017/09/11)
The enantioselective catalytic alkynylation of aromatic aldehydes is reported using a sterically highly hindered bis-cyclometalated rhodium-based Lewis acid catalyst featuring the octahedral metal as the only stereogenic center. Yields of 58-98% with 79-9
Base-Promoted Tandem Reaction towards Conjugated Dienone or Chromone Derivatives with a Cyano Group: Insertion of Alkynes into C–C σ-Bonds of 3-Oxopropanenitriles
Yao, Qiyi,Kong, Lingkai,Zhang, Fangfang,Tao, Xianghua,Li, Yanzhong
supporting information, p. 3079 - 3084 (2017/09/13)
Base-promoted insertion reactions of alkynes into the C–C σ-bonds of α-cyano ketones were established to construct highly functionalized conjugated olefins or chromone derivatives via transition metal-free tandem reactions. These reactions are initialized through the nucleophilic attack of α-cyano ketones to alkynones followed by intramolecular nucleophilic addition/ring-opening to furnish the cyano-containing alkenes. In the cases of alkynones bearing an ortho-halide-substituted aryl ring, a further C–O bond coupling reaction occurs to afford chromone derivatives in good to high yields. Various alkynones bearing alkyl or aryl substituents were compatible in the reaction. This reaction has the potential to become a general synthetic protocol for the preparation of cyano-substituted olefins and chromones due to the abundance of easily accessible starting materials possessing diverse substituent groups. (Figure presented.).
Synthesis of 2-Sulfenylindenones via One-Pot Tandem Meyer-Schuster Rearrangement and Radical Cyclization of Arylpropynols with Disulfides
Zhang, Xing-Song,Jiao, Jun-Ying,Zhang, Xiao-Hong,Hu, Bo-Lun,Zhang, Xing-Guo
, p. 5710 - 5716 (2016/07/13)
A tandem annulation of arylpropynols with disulfides has been developed for the synthesis of 2-sulfenylindenone derivatives. The reaction pathway involves one-pot tandem Meyer-Schuster rearrangement of arylpropynols and successive radical cyclization with disulfides. Various arylpropynols and disulfides with a number of functional groups are compatible in this reaction that affords the corresponding 2-sulfenylindenones in moderate to good yields.
A mild, highly efficient addition of alkynes to aldehydes catalyzed by titanium dioxide-supported silver nanoparticles
Yu, Min,Wang, Yong,Sun, Weijiang,Yao, Xiaoquan
supporting information; experimental part, p. 71 - 76 (2012/04/04)
Titanium dioxide-supported silver nanoparticles were utilized as a highly efficient catalyst for the addition of terminal alkynes to aldehydes to prepare propargylic alcohols with the promotion by triphenylphosphine. Both a significant support effect and a ligand effect were observed in the catalytic reaction. With this protocol, various propargylic alcohol derivatives were synthesized from aldehydes and terminal alkynes in good to excellent yields. Furthermore, the catalyst could be recovered and reused effectively without obvious reduction in catalytic activity.
Enantioselective alkynylation of aldehydes with 1-haloalkynes catalyzed by tethered bis(8-quinolinato) chromium complex
Usanov, Dmitry L.,Yamamoto, Hisashi
, p. 1286 - 1289 (2011/04/16)
The first example of Cr-catalyzed asymmetric alkynylation of aldehydes with 1-iodo- and 1-bromoalkynes was developed. The use of tethered bis(8-quinolinato) chromium catalyst (3 mol %) allowed preparation of enantioenriched propargyl alcohols with good yields and enantioselectivities up to 92% ee. 1-Bromoalkynes can be activated by the introduction of a cobalt porphine cocatalyst, which enables shorter reaction times without any loss of enantiocontrol.
