نتایج جستجو برای: fluorinated enones

تعداد نتایج: 4816  

2009
Zvonimir Maksić Ladislav Éhn Ivan Černušák Pavel Neogrády

Dipole polarizabilities of fluorinated C2 and C3 hydrocarbons have been studied using Coupled Cluster theory including single, double and non-iterative triple substitutions (CCSD(T)) – in conjunction with three basis sets: Pol, Z3Pol and HyPol. All molecular geometries were optimized at the MP2/aug-ccpVTZ level. We have found only small effects of electron correlation on electric properties in ...

Journal: :Organic & biomolecular chemistry 2011
Yi-Xian Li Mu-Hua Huang Yukiko Yamashita Atsushi Kato Yue-Mei Jia Wu-Bao Wang George W J Fleet Robert J Nash Chu-Yi Yu

L-DMDP and L-homoDMDP, the enantiomers of naturally occurring DMDP and homoDMDP have been synthesized from D-xylose derived cyclic nitrone 9. Their 3-deoxy-3-fluorinated analogues were also obtained from polyhydroxylated fluorinated cyclic nitrone 10, which was prepared from fluorinated sugar 12 in seven steps. Bioactivities of these iminosugars against various glycosidases were evaluated. Whil...

Journal: :Acta chimica Slovenica 2013
Samikannu Ramesh Appaswami Lalitha

A novel and practical method has been developed for the synthesis of β-cyanoketones using tetraethylammonium cyanide (Et4NCN, TEACN) / Sc(III) triflate and chalcones without the liberation of toxic HCN gas. Availability, safety, easy handling of the reagents, mild conditions of the reaction and high yields, make this method an attractive protocol for the direct synthesis of cyano substituted 1,...

2016
Tuo Jiang Xu Quan Can Zhu Pher G. Andersson Jan‐E. Bäckvall

We report a palladium-catalyzed oxidative functionalization of alkynes to generate α-acetoxylated enones in one step. A range of functional groups are well-tolerated in this reaction. Mechanistic studies, including the use of (18) O-labeled DMSO, revealed that the ketone oxygen atom in the product originates from DMSO.

Journal: :Organic & biomolecular chemistry 2013
Lingjuan Zhang Xianxiu Xu Qiu-rong Shao Ling Pan Qun Liu

A new reaction model, tandem Michael addition/formal isocyanide insertion into the acyl C-C bond, has been developed. Thus, a series of 2-acylpyrroles and seven-/eight-membered ring fused pyrroles were synthesized from the reaction of methyl isocyanides with enones in a single operation.

Journal: :Chemical communications 2013
Thomas Klatt Klaus Groll Paul Knochel

Various functionalized aryl and heteroaryl aluminum reagents were obtained by performing I-Li or Br-Li exchange reactions with the corresponding unsaturated organic halides in the presence of i-Bu2AlCl. By means of an appropriate catalyst, the resulting new aluminum species were directly acylated, allylated or arylated. 1,4-Michael additions to enones have also been achieved.

Journal: :Organic letters 2013
Junming Mo Ruojie Yang Xingkuan Chen Bhoopendra Tiwari Yonggui Robin Chi

A direct α-functionalization of simple aldehydes under N-Heterocyclic Carbene (NHC) catalysis and direct generation of ester enolate equivalents from nonfunctionalized aldehydes are disclosed. The catalysis involves selective enolate generation from an oxidatively generated NHC-bounded ester intermediate as a key step. The ester enolate intermediates undergo stereoselective reactions with enone...

Journal: :Angewandte Chemie 2014
Zhenqian Fu Ke Jiang Tingshun Zhu Jaume Torres Yonggui Robin Chi

Organocatalytic ester activation is developed for a highly selective cascade reaction between saturated esters and amino enones. The reaction involves activation of the β-carbon atom of the ester as a key step. This method allows a single-step access to multicyclic oxoquinoline-type heterocycles with high enantiomeric ratios.

Journal: :Chemical & pharmaceutical bulletin 2012
Ryosuke Okuno Jun-ichi Matsuo Hiroyuki Ishibashi

β'-Chloro and β',γ'-unsaturated trichlorotitanium enolates, which were formed in situ by titanium(IV) chloride-mediated ring cleavage of 3,3-dialkylcyclobutanones and 3-[(trimethylsilyl)methyl]cyclobutanones, reacted with enones to give Michael adducts with keeping a labile β'-chloro or β',γ'-unsaturated group.

Journal: :Chemical communications 2014
Amparo Sanz-Marco Andrea García-Ortiz Gonzalo Blay José R Pedro

The first enantioselective conjugate alkynylation of β-trifluoromethyl α,β-enones using terminal alkynes and a taniaphos-Cu(I) complex as catalyst is described. Ketones bearing a trifluoromethylated propargylic chiral centre in the β-position were obtained with good yields and high enantiomeric excesses (up to 99%).

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