64214-60-4Relevant academic research and scientific papers
Selective Synthesis of Z-Silyl Enol Ethers via Ni-Catalyzed Remote Functionalization of Ketones
Guven, Sinem,Kundu, Gourab,Rissanen, Kari,Schoenebeck, Franziska,Ward, Jas S.,We?els, Andrea
supporting information, p. 8375 - 8380 (2021/06/27)
We report a remote functionalization strategy, which allows the Z-selective synthesis of silyl enol ethers of (hetero)aromatic and aliphatic ketones via Ni-catalyzed chain walking from a distant olefin site. The positional selectivity is controlled by the directionality of the chain walk and is independent of thermodynamic preferences of the resulting silyl enol ether. Our mechanistic data indicate that a Ni(I) dimer is formed under these conditions, which serves as a catalyst resting state and, upon reaction with an alkyl bromide, is converted to [Ni(II)-H] as an active chain-walking/functionalization catalyst, ultimately generating a stabilized η3-bound Ni(II) enolate as the key selectivity-controlling intermediate.
Total Synthesis and Antitrypanosomal Activity of Janadolide and Simplified Analogues
Chung, Jonathan H.,Corcilius, Leo,Geraghty, Kieran,Kaiser, Marcel,Payne, Richard J.,Tang, Arthur H.
supporting information, (2020/04/20)
Janadolide is a cyclic depsipeptide natural product isolated from the marine cyanobacterium Okeania sp. Herein, we describe the total synthesis of janadolide, along with eight simplified analogues, via an efficient solid-phase strategy. Crucial to the synthesis of the natural product was the construction of a key polyketide fragment via an enantioselective (-)-B-chlorodiisopinocampheylborane-mediated reduction and a B-alkyl Suzuki reaction. Janadolide and the simplified analogues exhibited antitrypanosomal activity against pathogenic Trypanosoma brucei rhodesiense and Trypanosoma cruzi parasites.
Potent Analogues of Abscisic Acid – Identifying Cyano-Cyclopropyl Moieties as Promising Replacements for the Cyclohexenone Headgroup
Frackenpohl, Jens,Bojack, Guido,Baltz, Rachel,Bickers, Udo,Busch, Marco,Dittgen, Jan,Franke, Jana,Freigang, J?rg,Grill, Erwin,Gonzalez, Susana,Helmke, Hendrik,Hills, Martin J.,Hohmann, Sabine,von Koskull-D?ring, Pascal,Kleemann, Jochen,Lange, Gudrun,Lehr, Stefan,Schmutzler, Dirk,Schulz, Arno,Walther, Kerstin,Willms, Lothar,Wunschel, Christian
, p. 1416 - 1425 (2018/04/06)
Synthetic analogues of plant hormone abscisic acid (ABA) bearing a yet unexplored head group motif were prepared based on a combination of agrochemical experience, in vivo hits and structure-based design. It could thus be explored how modifying key parts of ABA's cyclohexenone unit influenced receptor affinity and in vivo efficacy against drought stress in selected crops. Cyano-cyclopropyl groups proved to be suitable replacements of the cyclohexanone moiety leading to ABA analogues with strong activity in vitro and in vivo. Their efficient and versatile synthesis proceeded via Stille or Sonogashira couplings as the key steps. Combining novel cyano-cyclopropyl headgroups with previously identified substituents in the terpenoid side chain afforded the most promising effects against drought stress in crops, particularly canola and wheat.
One-pot transition-metal-free synthesis of weinreb amides directly from carboxylic acids
Niu, Teng,Wang, Ke-Hu,Huang, Danfeng,Xu, Changming,Su, Yingpeng,Hu, Yulai,Fu, Ying
, p. 320 - 330 (2014/02/14)
Weinreb amides were prepared directly from carboxylic acids, N,O-dimethylhydroxylamine, and phosphorus trichloride in one pot at 60 °C in toluene in high yields, thus avoiding the separation of the moisture and air sensitive intermediate P[NMe(OMe)]3 in advance. Sterically hindered carboxylic acids also give the corresponding Weinreb amides in excellent yields. Various functional groups are tolerated on the carboxylic acid. The method, which is a simple process and gives high yields, is suitable for large-scale production. Georg Thieme Verlag KG Stuttgart · New York.
Highly efficient and environmentally benign preparation of Weinreb amides in the biphasic system 2-MeTHF/water
Pace, Vittorio,Castoldi, Laura,Alcantara, Andres R.,Holzer, Wolfgang
, p. 10158 - 10162 (2013/09/02)
A straightforward chromatography-free preparation of Weinreb amides starting from acid halides has been achieved in the biphasic medium 2-MeTHF/water. Analytically pure compounds were isolated in excellent yields simply after removal of 2-MeTHF, which abs
Modified shapiro reactions with bismesitylmagnesium as an efficient base reagent
Kerr, William J.,Morrison, Angus J.,Pazicky, Marek,Weber, Tina
supporting information; experimental part, p. 2250 - 2253 (2012/06/30)
Bismesitylmagnesium has been shown to successfully mediate the Shapiro reaction. A range of tosylhydrazones has been subjected to the developed system, which furnishes exceptionally high incorporation of the introduced electrophiles and good yields of the functionalized styrenes. At conveniently accessible temperatures and with a comparably small excess of base reagent, this protocol offers an efficient alternative to the lithium-mediated process. Importantly, 1.05 equiv of Weinreb amides are sufficient to obtain aryl enones in good yields.
Ru-catalyzed hydrogenation of 3,5-diketo amides: Simultaneous control of chemo- and enantioselectivity
Li, Wanfang,Fan, Weizheng,Ma, Xin,Tao, Xiaoming,Li, Xiaoming,Xie, Xiaomin,Zhang, Zhaoguo
supporting information, p. 8976 - 8978 (2012/11/07)
By modulating the chelating priorities of the different directing groups in 3,5-diketo amides with the assistance from coordinating solvent, highly chemo- and enantioselective hydrogenation of the C3-carbonyls was achieved in the presence of [RuCl(benzene)(S)-SunPhos]Cl in THF.
Ruthenium-catalyzed reduction of N-alkoxy- and N-hydroxyamides
Fukuzawa, Hiroko,Ura, Yasuyuki,Kataoka, Yasutaka
experimental part, p. 3643 - 3648 (2011/12/02)
A ruthenium-catalyzed reduction of N-alkoxy- and N-hydroxyamides was found to afford corresponding amides in good to high yields. A simple RuCl 3/Zn-Cu/alcohol system, without the addition of any other ligands, exhibited a high catalytic activity, and therefore the present reaction does not require a stoichiometric amount of metals or metal complexes as reductants. When β-substituted-α,β-unsaturated N-methoxyamides were employed as substrates, concurrent hydrogenation of the olefin moiety proceeded slowly with deprotection of the methoxy group. In the reduction of N-hydroxyamides, the alcoholic solvent was found to function as a hydrogen donor.
A powerful reagent for synthesis of weinreb amides directly from carboxylic acids
Niu, Teng,Zhang, Weiming,Huang, Danfeng,Xu, Changming,Wang, Haifeng,Hu, Yulai
scheme or table, p. 4474 - 4477 (2009/12/24)
A powerful reagent, P[NCH3(OCH3)]3 (3), for conversion of carboxylic acids directly to Weinreb amides was developed. In most cases the yields of the corresponding Weinreb amides were above 90% when P[NCH3(OCHsu
