50684-40-7Relevant academic research and scientific papers
Ir/f-Ampha complex catalyzed asymmetric sequential hydrogenation of enones: a general access to chiral alcohols with two contiguous chiral centers
He, Lin,Li, Ruihao,Li, Wendian,Long, Jiao,Lv, Hui,Song, Nan,Yang, Tilong,Zhang, Xumu
, p. 1808 - 1814 (2022/02/21)
A general and highly efficient method for asymmetric sequential hydrogenation of α,β-unsaturated ketones has been developed by using an iridium/f-Ampha complex as the catalyst, furnishing corresponding chiral alcohols with two contiguous stereocenters in high yields with excellent diastereo- and enantioselectivities (up to 99% yield, >20?:?1 dr and >99% ee). Control experiments indicated that the CC and CO bonds of the enones were hydrogenated sequentially, and the final stereoselectivities were determined by the dynamic kinetic resolution of ketones. Moreover, DFT calculations revealed that an outer sphere pathway was involved in both reduction of CC and CO bonds of enones. The synthetic utility of this method was demonstrated by a gram-scale reaction with very low catalyst loading (S/C = 20?000) and a concise synthetic route to key chiral intermediates of the antiasthmatic drug CP-199,330. This journal is
Redox-Neutral Coupling between Two C(sp3)?H Bonds Enabled by 1,4-Palladium Shift for the Synthesis of Fused Heterocycles
Rocaboy, Ronan,Anastasiou, Ioannis,Baudoin, Olivier
supporting information, p. 14625 - 14628 (2019/09/16)
The intramolecular coupling of two C(sp3)?H bonds to forge a C(sp3)?C(sp3) bond is enabled by 1,4-Pd shift from a trisubstituted aryl bromide. Contrary to most C(sp3)?C(sp3) cross-dehydrogenative couplings, this reaction operates under redox-neutral conditions, with the C?Br bond acting as an internal oxidant. Furthermore, it allows the coupling between two moderately acidic primary or secondary C?H bonds, which are adjacent to an oxygen or nitrogen atom on one side, and benzylic or adjacent to a carbonyl group on the other side. A variety of valuable fused heterocycles were obtained from easily accessible ortho-bromophenol and aniline precursors. The second C?H bond cleavage was successfully replaced with carbonyl insertion to generate other types of C(sp3)-C(sp3) bonds.
Metal-free desulfonylation reaction through visible-light photoredox catalysis
Yang, Deng-Tao,Meng, Qing-Yuan,Zhong, Jian-Ji,Xiang, Ming,Liu, Qiang,Wu, Li-Zhu
, p. 7528 - 7532 (2013/12/04)
The desulfonylation of β-arylketosulfones has been achieved in good to excellent yields by using 3-W blue LEDs light, 1 mol-% organic dye eosin Y bis(tetrabutylammonium salt) as photocatalyst, and diisopropylethylamine as reducing agent. Mechanistic studies demonstrate that oxidative quenching of the excited eosin Y by β-arylketosulfones plays a crucial role in the present photoredox catalytic cycle. Reductive desulfonylation is essential to enable to use of a sulfone as an auxiliary group. For reductive removal of sulfones, highly aggressive metal-containing reducing agents and harsh reaction conditions are often employed. In this paper, metal-free desulfonylation of β-arylketosulfones can be achieved efficiently at room temperature under visible-light irradiation.
Synthesis and antirhinovirus activity of new 3-benzyl chromene and chroman derivatives
Conti, Cinzia,Desideri, Nicoletta
experimental part, p. 3720 - 3727 (2009/10/02)
A series of 3-benzyl chromenes and chromans were synthesized and tested in vitro against human rhinovirus (HRV) 1B and 14, two representative serotypes for rhinovirus group B and A, respectively. All the new compounds, with the exception of 3-benzyl-2H-chromene (3a), showed a potent activity against HRV serotype 1B within micro or submicromolar range (IC50s from 0.11 to 6.62 μM). The low cytotoxicity of all the derivatives resulted in compounds with high therapeutic index (TI). On the contrary, HRV 14 infection was only weakly inhibited by the majority of these compounds. The 3-benzylidenechromans 2b and 2c showed the highest anti-HRV 1B activity (IC50 0.12 and 0.11 μM, respectively) coupled with remarkable TI (625.00 and 340.91, respectively). Mechanism of action studies on (Z)-3-(4-chlorobenzylidene)chroman (2b) suggest that the new compounds behave as capsid binders and interfere with very early stages of HRV 1B replication, similarly to related flavanoids.
Photochemical reductive desulfonylation of β-ketosulfones by ascorbic acid
Liu, Qiang,Han, Bing,Liu, Zhengang,Yang, Li,Liu, Zhong-Li,Yu, Wei
, p. 1805 - 1807 (2007/10/03)
Photoinduced electron-transfer reaction between excited β-ketosulfones and ascorbic acid provides an efficient and green approach for the desulfonylation of β-ketosulfones.
New convenient synthesis of homoisoflavanones and (±)-di-O- methyldihydroeucomin
Kirkiacharian, B. Serge,Gomis, Michel
, p. 563 - 569 (2007/10/03)
Upon reaction of 1-(2-hydroxyphenyl)-3-phenylpropane-1-ones (2′-hydroxydihydrochalcones) with dimethylaminodimethoxymethane in boiling toluene, the corresponding 3-benzylchromones are obtained in excellent yields. These latter lead to 3-benzylchroman-4-on
Asymmetric synthesis of cyclic hydroxy ketones derived from enol ethers via sharpless asymmetric dihydroxylation. A study in the correlation of the enol ether chain length and enantioselectivity
Marcune, Benjamin F.,Karady, Sandor,Reider, Paul J.,Miller, Ross A.,Biba, Mirlinda,DiMichele, Lisa,Reamer, Robert A.
, p. 8088 - 8091 (2007/10/03)
The Sharpless asymmetric dihydroxylation reaction of enol ethers derived from their corresponding cyclic ketones, gave α-hydroxyketones with high enantioselectivity. The enantiomeric excess was found to be proportional to the length of the unbranched enol ether chain with a maximum ee for the pentyl enol ether. An efficient synthesis of α-hydroxy chromanone in >90% ee was demonstrated using this method.
Reactivity of α-arylidene benzoheteracyclanone dibromides toward azide ion: An effective approach to 3-(α-substituted-benzyl)chromones and -1-thiochromones
Patonay,Dinya,Lévai,Molnár
, p. 2895 - 2907 (2007/10/03)
Treatment of dibromides of 3-arylidenechromanones and -1-thiochromanones with sodium azide resulted in the formation of 3-(α-azidobenzyl)chromones and -1-thiochromones whereas dibromides having no antiperiplanar vicinal hydrogen in the ring such as flavanone, 1-thioflavanone and benzosuberone derivatives afforded only the parent enones by bromine elimination. Evidence supported the intermediacy of 3-(α-bromobenzyl)chromones and -1-thiochromones in this reaction. These postulated intermediates were prepared in an independent way and transformed into azides in high yield.
Tributylstannane-Mediated Cyclization of Thionocarboxylic Acid Derivatives
Bacchi, Mario D.,Bosch, Eric,Denenmark, Daniella,Girsh, Diana
, p. 6803 - 6810 (2007/10/02)
Cyclization reactions of various thionoesters and thioamides involving the addition of tri-n-butylstannyl radical to a thiocarbonyl group and intramolecular addition of the resulting radical to a carbon-carbon multiple bond was studied.Dithiocarbonate and (imidazolyl)thiocarbonyl derivatives of homoallylic alcohols gave α-substituted γ-thionobutyrolactones.The reaction is highly dependent on the substitution pattern on the double bond, a high yield of products being obtained only when the double bond is activated and unhindered. (Z)-4-Phenylbut-3-enyl thionobenzoate afforded 4,5-dihydro-2-phenyl-3-benzylfuran in low yield.In reactions involving a thioamide group, good yields of cyclic products were obtained only from compounds in which the electron density on the nitrogen atom is decreased by an electron attracting group.Cyclization of 1-((E)-4-phenylbut-3-en-1-yl)-5-thioxopyrrolidin-2-one (23) afforded 1-aza-4-benzylbicyclooct-4-en-8-one (33).
PALLADIUM CATALYSED ARYLATION OF CHROM-3-EN-4-OL ACETATES VIA THEIR TRIBUTYLTIN ENOLATES
Donnelly, Dervilla M.X.,Finet, Jean-Pierre,Stenson, Paul H.
, p. 15 - 18 (2007/10/02)
Arylation of in situ generated chrom-3-en-4-ol tributyltin enolates with aryl bromide in the presence of a catalytic amount of PdCl22 gives moderate to good yields of the corresponding isoflavanones.
