2050-51-3Relevant academic research and scientific papers
Iron-Catalyzed Anti-Markovnikov Hydroamination and Hydroamidation of Allylic Alcohols
Ma, Wei,Zhang, Xiaohui,Fan, Juan,Liu, Yuxuan,Tang, Weijun,Xue, Dong,Li, Chaoqun,Xiao, Jianliang,Wang, Chao
supporting information, p. 13506 - 13515 (2019/09/09)
Hydroamination allows for the direct access to synthetically important amines. Controlling the selectivity of the reaction with efficient, widely applicable, and economic catalysts remains challenging, however. This paper reports an iron-catalyzed formal anti-Markovnikov hydroamination and hydroamidation of allylic alcohols, which yields γ-amino and γ-amido alcohols, respectively. Homoallylic alcohol is also feasible. The catalytic system, consisting of a pincer Fe-PNP complex (1-4 mol %), a weak base, and a nonpolar solvent, features exclusive anti-Markovnikov selectivity, broad substrate scope (>70 examples), and good functional group tolerance. The reaction could be performed at gram scale and applied to the synthesis of drug molecules and heterocyclic compounds. When chiral substrates are used, the stereochemistry and enantiomeric excess are retained. Further application of the chemistry is seen in the functionalization of amino acids, natural products, and existing drugs. Mechanistic studies suggest that the reaction proceeds via two cooperating catalytic cycles, with the iron complex catalyzing a dehydrogenation/hydrogenation process while the amine substrate acts as an organocatalyst for the Michael addition step.
Efficient Syntheses of Diverse, Medicinally Relevant Targets Planned by Computer and Executed in the Laboratory
Klucznik, Tomasz,Mikulak-Klucznik, Barbara,McCormack, Michael P.,Lima, Heather,Szymku?, Sara,Bhowmick, Manishabrata,Molga, Karol,Zhou, Yubai,Rickershauser, Lindsey,Gajewska, Ewa P.,Toutchkine, Alexei,Dittwald, Piotr,Startek, Micha? P.,Kirkovits, Gregory J.,Roszak, Rafa?,Adamski, Ariel,Sieredzińska, Bianka,Mrksich, Milan,Trice, Sarah L.J.,Grzybowski, Bartosz A.
supporting information, p. 522 - 532 (2018/03/21)
The Chematica program was used to autonomously design synthetic pathways to eight structurally diverse targets, including seven commercially valuable bioactive substances and one natural product. All of these computer-planned routes were successfully executed in the laboratory and offer significant yield improvements and cost savings over previous approaches, provide alternatives to patented routes, or produce targets that were not synthesized previously. Although computers have demonstrated the ability to challenge humans in various games of strategy, their use in the automated planning of organic syntheses remains unprecedented. As a result of the impact that such a tool could have on the synthetic community, the past half century has seen numerous attempts to create in silico chemical intelligence. However, there has not been a successful demonstration of a synthetic route designed by machine and then executed in the laboratory. Here, we describe an experiment where the software program Chematica designed syntheses leading to eight commercially valuable and/or medicinally relevant targets; in each case tested, Chematica significantly improved on previous approaches or identified efficient routes to targets for which previous synthetic attempts had failed. These results indicate that now and in the future, chemists can finally benefit from having an “in silico colleague” that constantly learns, never forgets, and will never retire. Multistep synthetic routes to eight structurally diverse and medicinally relevant targets were planned autonomously by the Chematica computer program, which combines expert chemical knowledge with network-search and artificial-intelligence algorithms. All of the proposed syntheses were successfully executed in the laboratory and offer substantial yield improvements and cost savings over previous approaches or provide the first documented route to a given target. These results provide the long-awaited validation of a computer program in practically relevant synthetic design.
Convergent synthesis of dronedarone, an antiarrhythmic agent
Okitsu, Takashi,Ogasahara, Mizuki,Wada, Akimori
, p. 1149 - 1153 (2016/08/11)
We have developed a convergent synthesis of dronedarone, an antiarrhythmic agent. The key steps of the process are the construction of a benzofuran skeleton by iodocyclization and the carbonylative Suzuki-Miyaura cross-coupling for biaryl ketone formation. This synthetic route required only eight steps from 2-amino-4-nitrophenol in 23% overall yield.
Omega-quaternary ammonium alkyl esters and thioesters of acidic nonsteroidal antiinflammatory drugs
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, (2008/06/13)
Quaternary ammonium alkyl esters and thioesters of acidic nonsteroidal anti-inflammatory drugs (NSAIDs) are disclosed. These esters and thioesters display the anti--inflammatory profile of the parent NSAIDs with greatly reduced gastrointestinal irritancy, providing a more favorable separation of therapeutic activity and toxicological side effects than the parent NSAIDs.
2'-(4,6-Disubstituted)-s-triazin-2-yl)amino-6'-dialkylamino flurans
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, (2008/06/13)
Fluorans useful as color precursors, particularly in the art of carbonless duplicating are normally colorless and are represented by the structural formula STR1 wherein R represents non-tertiary alkyl of one to four carbon atoms; R1 and R2 represent hydrogen or non-tertiary alkyl of one to four carbon atoms; R3 and R4 represent chlorine, NH2 or one of the groups --NR5 -(lower-alkylene)-N(R6)(R7), --NR5 -(lower-alkylene-N(R8)(R9)(R10) An, -NR5 -(lower-alkylene)-OH, -NR5 -(lower-alkylene) STR2 --NR5 -(HSO3 -C6 H4) or --O-(lower-alkylene)-N(R8)(R9) in which R5, R6 and R7 represent hydrogen or non-tertiary alkyl of one to four carbon atoms; R8 and R9 represent non-tertiary alkyl of one to four carbon atoms; R10 represents non-tertiary alkyl of one to four carbon atoms, benzyl or benzyl substituted in the benzene ring by one or two of halo or alkyl of one to three carbon atoms; and An represents an anion.
