28203-05-6Relevant articles and documents
Precatalyst-Enabled Selectivity: Enantioselective NiH-Catalyzed anti-Hydrometalative Cyclization of Alkynones to Endo- and Heterocyclic Allylic Alcohols
Li, Qi-Yang,Liu, Wen-Bo,Zeng, Hai-Xiang,Zhang, Xiao-Wen,Zhu, Ming-Hui
supporting information, p. 27225 - 27229 (2021/12/08)
A highly enantioselective NiH-catalyzed hydrocyclization of alkynones with unparalleled anti- and endocyclic selectivities is described. The choice of the precatalysts has significant influence in tuning the regio- and enantioselectivity. Using Ni(OTs)su
Preparation and Application of α-Imino Ketones through One-Pot Tandem Reactions Based on Heyns Rearrangement
Li, Ling,Zhang, Shiqi,Deng, Xiongfei,Li, Guangxun,Tang, Zhuo,Zhao, Gang
supporting information, p. 6819 - 6824 (2021/09/08)
α-Imino ketone is a useful building block for the preparation of α-amino ketones and α-amino alcohols. However, its preparation has been seldomly seen. Herein, a metal-free and operationally simple strategy has been developed to generate α-imino ketones with high regioselectivity. Meanwhile, the method allowed for the preparation of various N,O-ketals with high regioselectivities and diastereoselectivities through cascade reactions in one pot.
Distal Functional Group Migration for Visible-light Induced Carbo-difluoroalkylation/monofluoroalkylation of Unactivated Alkenes
Yu, Jiajia,Wang, Dongping,Xu, Yan,Wu, Zhen,Zhu, Chen
supporting information, p. 744 - 750 (2017/12/26)
A general and practical protocol for elusive carbo-difluoroalkylation/ monofluoroalkylation of unactivated alkenes based on the distal functional group migration is described. A portfolio of functional groups including heteroaryl, imino, formyl, and alkynyl groups showcase the migratory aptitude. In combination with visible-light photocatalysis, a broad range of di- and mono-fluorinated alkyl ketones are readily obtained in synthetically useful yields under mild reaction conditions. (Figure presented.).
Investigation and Application of Amphoteric α-Amino Aldehyde: An in Situ Generated Species Based on Heyns Rearrangement
Li, Guangxun,Tang, Ling,Liu, Hongxin,Wang, Yingwei,Zhao, Gang,Tang, Zhuo
supporting information, p. 4526 - 4529 (2016/09/28)
In situ generation of the reactive amphoteric α-amino aldehyde with simple α-hydroxy ketones and phenylamine via Heyns rearrangement was proven to be feasible. Metal-free domino reactions based on this reactive intermediate were effectively used to afford important N-heterocycles including polysubstituted pyrroles, indoles, and quinoxalines conveniently. A simple starting material, water as the only byproduct, and diversity of the useful products will make this method greatly attractive for pharmaceutics.
Efficient synthesis of 5′-fluoroalkoxythiazoles via α-bromo-α-fluoroalkoxyacetophenones Hantzsch type cyclization with thioureas or thioamides
Sokolenko, Taras M.,Davydova, Yulia A.,Yagupolskii, Yurii L.
scheme or table, p. 20 - 25 (2012/06/30)
Novel α-fluoroalkoxyacetophenones were synthesized by addition of the readily available 2,2-dimethoxy-2-phenylethanol to fluoroolefins. α-Bromination yielded α-bromo-α-fluoroalkoxyacetophenones, which on treatment with thioureas or thioamides gave thiazoles with fluoroalkoxy groups at the 5′-position by the Hantzsch-type cyclization. This provides a versatile methodology for the construction of heterocycles from aliphatic fluoroalkoxy containing building blocks.
Novel chemistry of α-tosyloxy ketones: Applications to the solution- and solid-phase synthesis of privileged heterocycle and enediyne libraries
Nicolaou,Montagnon,Ulven,Baran,Zhong,Sarabiat
, p. 5718 - 5728 (2007/10/03)
New synthetic technologies for the preparation and elaboration of α-tosyloxy ketones in solution and on solid-phase are described. Both olefins and ketones serve as precursors to these relatively stable chemical entities: olefins via a novel one-pot epoxi
Asymmetric Synthesis Using Chiral Acetals: Highly Diastereoselective Addition of Organocerium Reagents to Chiral α-Aldoxime-Ether Acetal
Fujioka, Hiromichi,Fuji, Masahiro,Okaichi, Yoshihiko,Yoshida, Takayuki,Annoura, Hirokazu,et al.
, p. 602 - 605 (2007/10/02)
Nucleophilic addition of organometallic reagents to the chiral α-aldoxime-ether acetal (1) was studied.Among the reagents, organocerium reagents showed higher reactivity and stereoselectivity, giving the N-oxygenated chiral amine derivatives (6Aa-c) in a highly diastereoselective manner, whereas Grignard and organolithium reagents afforded no 6.As an application of the reaction, the synthesis of (-)-N-acetylamphetamine (11) was achieved.
The Reactions of α-Arylsulfonoxy Ketones with Nucleophiles
Hoffman, Robert V.,Jankowski, Bryan C.,Carr, C. Sean,Duesler, Eileen N.
, p. 130 - 135 (2007/10/02)
α-(p-Nitrophenyl)sulfonoxy ketones can be converted to α-hydroxy ketals and α-hydroxy ketones by reaction with potassium carbonate and basic or acidic workup, respectively.They also react with amines to give α-amino ketones in high yields.Nonnucleophilic amines give an intramolecular aromatic substitution in the derived enolate.Factors which dictate the reaction patterns in these compounds are discussed.
Capture of Electron-Deficient Species with Aryl Halides. New Syntheses of Hypervalent Iodonium Ylides
Moriarty, Robert M.,Bailey, B. R. III,Prakash, Om,Prakash, Indra
, p. 1375 - 1378 (2007/10/02)
We have demonstrated the aryl iodide capture of β-diketocarbenes, generated from the diazo compound by using rhodium(II) acetate, under very mild conditions.This is a useful general preparative method for iodonium ylides under non-hydroxylic conditions.The termal, catalytic, and photochemical decompositions of various azides in the presence of aryl iodides were carried out.With highly reactive nitrenes, intramolecular rearrangement takes precedence over capture.In the case of p-tuloenesulfonyl azide, thermolysis in the presence of aryl iodides requires conditions under which the iminoiodane is itself decomposed.The capture of oxene by iodobenzene is discussed.The application of these capture processes is discussed as a synthetic route to hypervalent ylides as well as on the basis of mechanism.
