91388-25-9Relevant academic research and scientific papers
A Transient Directing Group Strategy Enables Enantioselective Multicomponent Organofluorine Synthesis
Liu, Zhonglin,Oxtoby, Lucas J.,Liu, Mingyu,Li, Zi-Qi,Tran, Van T.,Gao, Yang,Engle, Keary M.
supporting information, p. 8962 - 8969 (2021/07/01)
The vicinal fluorofunctionalization of alkenes represents an expedient strategy for converting feedstock olefins into valuable fluorinated molecules and as such has garnered significant attention from the synthetic community; however, current methods remain limited in terms of scope and selectivity. Here we report the site-selective palladium-catalyzed three-component coupling of alkenylbenzaldehydes, arylboronic acids, and N-fluoro-2,4,6-trimethylpyridinium hexafluorophosphate facilitated by a transient directing group. The synthetically enabling methodology constructs vicinal stereocenters with excellent regio-, diastereo-, and enantioselectivities, forging products that map onto bioactive compounds.
Catalytic Systems for Production of 1-Hexene by Selective Ethylene Trimerization
Afanas’ev, V. V.,Bespalova, N. B.,Cheredilin, D. N.,Kozlova, G. A.,Senin, A. A.,Sheloumov, A. M.
, p. 55 - 68 (2020/02/25)
Abstract: New chromium complexes with diphosphine ligands have been obtained by the reaction of chromium(III) hexahydrate and diphosphines in acetone. The structure of chromium(III) complex 4 containing water molecule and 1,2-bis(diphenylphosphino)benzene as ligands and that of two chromium(III) complexes (12 and 13) with 1,2-bis(diphenylphosphino)benzene ligands containing alkenyl substituents in the ortho-position of one of the phenyl groups at the phosphorous atom have been determined using X-ray diffraction analysis. The catalytic properties of the obtained complexes in the composition of catalytic systems for ethylene trimerization have been studied. It has been shown that the obtained series of catalytic systems manifests high activity in the process of ethylene trimerization to 1-hexene, with the process selectivity exceeding 94%. The highest value of productivity amongst known selective catalytic systems for trimerization was achieved using a chromium complex 13 bearing the 2-methylprop-1-enyl group at the ortho-position of one of the phenyl groups. The influence of temperature, pressure, the nature of the solvent and the composition of the catalytic system on the parameters of the process of ethylene trimerization to form 1-hexene has been determined.
Host-Catalyzed Cyclodehydration–Rearrangement Cascade Reaction of Unsaturated Tertiary Alcohols
Catti, Lorenzo,P?thig, Alexander,Tiefenbacher, Konrad
supporting information, p. 1331 - 1338 (2017/04/18)
The Br?nsted acidic resorcin[4]arene hexamer can be applied as an effective catalyst in the dehydrative cyclization and subsequent rearrangement of unsaturated tertiary alcohols. This is the first report on catalyzing such a reaction with a Br?nsted acid. Scope and limitations of this cyclopentene-forming reaction sequence are presented. Furthermore, substrate-selective conversion as well as competitive inhibition are described and provide evidence that the reactions proceed within the cavity of the self-assembled structure. Additionally, a cyclobutanone-forming intramolecular hydride transfer of an encapsulated cyclopropyl acetate is reported. (Figure presented.).
Exploiting the Biginelli reaction: Nitrogen-rich pyrimidine-based tercyclic α-helix mimetics
Lim, Zelong,Duggan, Peter J.,Wan, Soo San,Lessene, Guillaume,Meyer, Adam G.,Tuck, Kellie L.
, p. 1151 - 1160 (2016/02/16)
Several rationally designed pyrimidine-based scaffolds intended to mimic the spatial projection of the i, i+3, and i+7 residues of an α-helix and also possess improved aqueous solubility were prepared. A Biginelli-oxidation process was used to form the central pyrimidine ring of these scaffolds, which was subsequently manipulated to form pyrimidine-based tercyclic α-helix mimetics. A pyrimidine-based scaffold designed to mimic the α-helical BH3 domain of the pro-apoptotic Bak protein was also prepared as a putative inhibitor of the Bcl-xL/Bak protein-protein interaction. The pyrimidine-based tercyclic α-helix mimetics, and the putative Bcl-xL inhibitor, were assessed using a luminescence competition assay, however, none displayed inhibitory activity against Bcl-xL or Mcl-1.
Enantioselective Bromo-oxycyclization of Silanol
Xia, Zilei,Hu, Jiadong,Shen, Zhigao,Wan, Xiaolong,Yao, Qizheng,Lai, Yisheng,Gao, Jin-Ming,Xie, Weiqing
supporting information, p. 80 - 83 (2016/01/15)
Relying on the nucleophilicity of silanol for building up silicon-incorporated scaffold with an enantiopure tetrasubstituted carbon center remains elusive. In this report, asymmetric bromo-oxycyclization of olefinic silanol by using chiral anionic phase-transfer catalyst is described. This protocol provided a facile entry to a wide arrangement of enantiopure benzoxasilole in moderate to excellent enantioselectivities depending on the unique reactivity of bromine/N-benzyl-DABCO complex.
Gold(I)-catalyzed cycloisomerizations and alkoxycyclizations of ortho-(alkynyl)styrenes
Sanjun, Ana M.,Rashid, Muhammad A.,Garca-Garca, Patricia,Martnez-Cuezva, Alberto,Fernndez-Rodrguez, Manuel A.,Rodrguez, Flix,Sanz, Roberto
supporting information, p. 3042 - 3052 (2015/02/05)
Indenes and related polycyclic structures have been efficiently synthesized by gold(I)-catalyzed cycloisomerizations of appropriate ortho-(alkynyl)styrenes. Disubstitution at the terminal position of the olefin was demonstrated to be essential to obtain products originating from a formal 5-endo-dig cyclization. Interestingly, a complete switch in the selectivity of the cyclization of o-(alkynyl)-a-methylstyrenes from 6-endo to 5-endo was observed by adding an alcohol to the reaction media. This allowed the synthesis of interesting indenes bearing an all-carbon quaternary center at C1. Moreover, dihydrobenzo[a]fluorenes can be obtained from substrates bearing a secondary alkyl group at the β-position of the styrene moiety by a tandem cycloisomerization/1,2-hydride migration process. In addition, diverse polycyclic compounds were obtained by an intramolecular gold-catalyzed alkoxycyclization of o-(alkynyl)styrenes bearing a nucleophile in their structure. Finally, the use of a chiral gold complex allowed access to elusive chiral 1H-indenes in good enantioselectivities.
Photochemical studies on aromatic γ,δ-epoxy ketones: Efficient synthesis of benzocyclobutanones and indanones
Shao, Yutian,Yang, Chao,Gui, Weijun,Liu, Yang,Xia, Wujiong
supporting information; experimental part, p. 3560 - 3562 (2012/06/04)
Irradiation of terminal aromatic γ,δ-epoxy ketones with a 450 W UV lamp led to Norrish type II cyclization/semi-pinacol rearrangement cascade reaction which formed the benzocyclobutanones containing a full-carbon quaternary center, whereas irradiation of substituted aromatic γ,δ-epoxy ketones led to the indanones through a photochemical epoxy rearrangement and 1,5-biradicals cyclization tandem reaction.
Cyclization reaction for the synthesis of polysubstituted naphthalenes in the presence of Au(I) precatalysts
Jagdale, Arun R.,Park, Jong Hyub,Youn, So Won
experimental part, p. 7204 - 7215 (2011/10/17)
Au(I)-catalyzed cyclization of alkenyl carbonyl compounds leading to a variety of substituted naphthalenes has been developed. This process exploits a dual function of the Au(I) catalyst: (1) the oxophilic nature of the Au(I) catalyst, counterintuitive to the π-acidic reactivities generally associated with Au catalysts, and (2) olefin isomerization supported by the outcome of isotope scrambling experiments. It cannot be completely excluded that TfOH is a true operative catalyst in this protocol. In view of the practicality, the unnecessity of isomerically pure starting material in this reaction is particularly attractive and valuable.
Orthogonal synthesis of isoindole and isoquinoline derivatives from organic azides
Hui, Benjamin Wei-Qiang,Chiba, Shunsuke
supporting information; experimental part, p. 729 - 732 (2009/08/12)
(Chemical Equation Presented) α-Azido carbonyl compounds bearing a 2-alkenylaryl moiety at the α-position are found to be promising precursors for synthesis of isoindole and isoquinoline derivatives via 1,3-dipolar cycloaddrtion of azides onto alkenes and fcrelectrocyclization of N-H imine intermediates, respectively.
Metal-catalyzed cycloisomerization of enyne functionalities via a 1,3-alkylidene migration
Lin, Ming-Yuan,Das, Arindam,Liu, Rai-Shung
, p. 9340 - 9341 (2007/10/03)
We report a new metal-catalyzed 6-endo-dig cyclization of cis-4,6-dien-1-yn-3-ols, which produces substituted benzene and naphthalene derivatives with structural reorganization. In this process, we observe a 1,3-alkylidene migration via cleavage of the olefin double bond of the starting substrates. The ease and reliability of this cyclization are manifested by its compatibility with a wide array of diverse substrates and several π-alkyne activators, including PtCl2, Zn(OTf)2, AuCl, and AuCl3. Copyright
