52293-00-2Relevant academic research and scientific papers
Continuous flow as an enabling technology: a fast and versatile entry to functionalized glyoxal derivatives
Lima, Fabio,Meisenbach, Mark,Schenkel, Berthold,Sedelmeier, Joerg
supporting information, p. 2420 - 2424 (2021/04/02)
We herein report two complementary strategies employing organolithium chemistry for the synthesis of glyoxal derivatives. Micro-mixer technology allows for the generation of unstable organometallic intermediates and their instantaneous in-line quenching with esters as electrophiles. Selective mono-addition was observedviaputative stabilized tetrahedral intermediates. Advantages offered by flow chemistry technologies facilitate direct and efficient access to masked 1,2-dicarbonyl compounds while mitigating undesired by-product formation. These two approaches enable the production of advanced and valuable synthetic building blocks for heterocyclic chemistry with throughputs of grams per minute.
Fast and Efficient Continuous Flow Method for the Synthesis of Ynones and Pyrazoles
Kandasamy, Mohanraj,Ganesan, Balaji,Hung, Min-Yuan,Lin, Wei-Yu
supporting information, p. 3183 - 3189 (2019/05/28)
In this study, we developed a convenient and efficient two-step method for the synthesis of ynones in a flow reactor, through the generation of lithium acetylide and its subsequent reactions with acid chlorides. Using this approach, we obtained the ynones in moderate to good yields at room temperature. Moreover, we transformed the ynones into pyrazole derivatives through coupling with hydrazines. This transition metal-free process, mild reaction conditions, and broad functional group tolerance are all attractive features in comparison with conventional bench-top methods.
Mild Homologation of Esters through Continuous Flow Chloroacetate Claisen Reactions
Ganiek, Maximilian A.,Ivanova, Maria V.,Martin, Benjamin,Knochel, Paul
supporting information, p. 17249 - 17253 (2018/12/05)
The selective chloromethylenation of functionalized esters using chloroacetic acid (CA) and LiHMDS (HMDS=hexamethyldisilazide) in a continuous-flow setup is reported. This Claisen homologation is for the first time extended to bis-chloromethylenation using dichloroacetic acid (DCA), thus giving access to under-explored α,α′-bis-chloroketones. The use of flow conditions enables efficient generation and reaction of the unstable chloroacetate dianion intermediates, leading to unprecedented mild and scalable reaction conditions at an economical reagent stoichiometry (?10 °C, 1 min, 1.0–2.4 equiv dianion). The clean reaction profiles allow subsequent use of the unpurified crude products, which is demonstrated in the synthesis of various heterocycles of broad interest. Furthermore, we report a novel, catalyst-free substitution of the obtained monochloro ketone products with (hetero)aryl zinc enolates to give valuable 1,4-diketones.
Synthesis of new halo-containing acetylenes and their application to the synthesis of azoles
Martins, Marcos A.P.,Emmerich, Daniel J.,Pereira, Claudio M.P.,Cunico, Wilson,Rossato, Marcelo,Zanatta, Nilo,Bonacorso, Helio G.
, p. 4935 - 4938 (2007/10/03)
The convenient synthesis of ten halo- and an isoxazole-containing acetylenes from the reaction of acetylenes with n-butyl lithium and subsequent reaction with an electrophile agent (ethyl trichloroacetate, ethyl dichloroacetate, trifluoroacetic anhydride,
A Simple and Unambiguous Synthesis of α,α- and α,α'-Dihalogeno Ketones
Barluenga, Jose,Llavona, Lujan,Concellon, Jose M.,Yus, Miguel
, p. 297 - 300 (2007/10/02)
A convenient method for the unambiguous preparation of α,α'-dihalogeno ketones 3 from in situ-generated chloromethyllithium and α-chloro or α-bromo carboxylic acid esters 1 at -78 deg C, is described.The unambiguous prparation of α,α-dihalogeno ketones 7 by using in situ-generated dihalogenomethyllithium and carboxylic acid esters 5 at -78 deg C is also reported.
