27549-93-5Relevant academic research and scientific papers
Selective α-Deuteration of Cinnamonitriles using D2O as Deuterium Source
Guo, Beibei,de Vries, Johannes G.,Otten, Edwin
supporting information, p. 179 - 186 (2021/10/12)
The selective α-deuteration of α,β-unsaturated nitriles using the strong base tBuOK or a metal-ligand cooperative Ru pincer catalyst is described. With D2O as deuterium source and glyme as solvent at 70 °C, tBuOK is an efficient catalyst for deuteration at the α-C(sp2) position of cinnamonitriles, providing access to a broad range of deuterated derivatives in good to excellent yields and with very high levels of deuterium incorporation. While the tBuOK-catalysed protocol does not tolerate base-sensitive functional groups, cinnamonitrile derivatives containing a benzylic bromide or ester moiety were deuterated in excellent yields using Milstein's ruthenium PNN pincer catalyst. Moreover, the activity for H/D exchange of the metal-ligand cooperative Ru catalyst is found to be significantly higher than that of tBuOK, allowing reactions to proceed well even at room temperature. A mechanistic proposal is put forward that involves deprotonation of the cinnamonitrile α-CH position when using tBuOK as catalyst, whereas H/D exchange catalysis with the Ru PNN pincer likely proceeds via (reversible) oxa-Michael addition of D2O. (Figure presented.).
Stereoselective synthesis of cyclobutanes by contraction of pyrrolidines
Hui, Chunngai,Brieger, Lukas,Strohmann, Carsten,Antonchick, Andrey P.
, p. 18864 - 18870 (2021/11/23)
Here we report a contractive synthesis of multisubstituted cyclobutanes containing multiple stereocenters from readily accessible pyrrolidines using iodonitrene chemistry. Mediated by a nitrogen extrusion process, the stereospecific synthesis of cyclobutanes involves a radical pathway. Unprecedented unsymmetrical spirocyclobutanes were prepared successfully, and a concise, formal synthesis of the cytotoxic natural product piperarborenine B is reported.
Pd(II)-Catalyzed CC Bond Cleavage by a Formal Group-Exchange Reaction
Ye, Runyou,Zhu, Maoshuai,Yan, Xufei,Long, Yang,Xia, Ying,Zhou, Xiangge
, p. 8678 - 8683 (2021/07/26)
A chelation-assisted palladium-catalyzed CC bond cleavage of α, β-unsaturated ketone to form alkenyl nitrile in the presence of nitrile is disclosed on the basis of a formal group-exchange reaction formulated as C1C2 + C3 → C1C3 + C2, differing from normal alkene oxidative cleavage and metathesis type. The isolated key active Pd(II) complex as well as deuterium-labeled experiment revealed the necessity of the chelation group, and a plausible catalytic pathway was proposed.
An aerobic and green C-H cyanation of terminal alkynes
Si, Yi-Xin,Zhang, Song-Lin,Zhu, Peng-Fei
supporting information, p. 9216 - 9220 (2020/12/03)
This study describes a benign C-H cyanation of terminal alkynes with α-cyanoesters serving as a nontoxic cyanide source. In situ generation of the key copper cyanide intermediate is proposed by a sequence of α-C-H oxidation and copper-mediated β-carbon elimination of α-cyanoesters, releasing the α-ketoester byproduct observed experimentally. The ensuing reaction of copper cyanide with terminal alkynes delivers preferentially cyanoalkynes and surpasses the possible Glaser type dimerization of terminal alkynes or the undesired accumulation of HCN under protic conditions. The presence of the co-oxidant K2S2O8 is crucial to this selectivity, probably by promoting oxidative transmetalation and the resulting formation of the Cu(iii)(acetylide)(CN) intermediate. All the reagents and salts used are commercially available, cheap and nontoxic, avoiding the use of highly toxic cyanide salts typically required in cyanation studies. The scope of this reaction is demonstrated with a set of alkynes and α-cyanoesters. The application of this method to late-stage functionalization of the terminal alkyne group in an estrone derivative is also feasible, showing its practical value for drug design.
Comprehensive structure-activity-relationship of azaindoles as highly potent FLT3 inhibitors
Grimm, Sebastian H.,Gagestein, Berend,Keijzer, Jordi F.,Liu, Nora,Wijdeven, Ruud H.,Lenselink, Eelke B.,Tuin, Adriaan W.,van den Nieuwendijk, Adrianus M.C.H.,van Westen, Gerard J.P.,van Boeckel, Constant A.A.,Overkleeft, Herman S.,Neefjes, Jacques,van der Stelt, Mario
supporting information, p. 692 - 699 (2019/01/22)
Acute myeloid leukemia (AML) is characterized by fast progression and low survival rates, in which Fms-like tyrosine kinase 3 (FLT3) receptor mutations have been identified as a driver mutation in cancer progression in a subgroup of AML patients. Clinical trials have shown emergence of drug resistant mutants, emphasizing the ongoing need for new chemical matter to enable the treatment of this disease. Here, we present the discovery and topological structure-activity relationship (SAR) study of analogs of isoquinolinesulfonamide H-89, a well-known PKA inhibitor, as FLT3 inhibitors. Surprisingly, we found that the SAR was not consistent with the observed binding mode of H-89 in PKA. Matched molecular pair analysis resulted in the identification of highly active sub-nanomolar azaindoles as novel FLT3-inhibitors. Structure based modelling using the FLT3 crystal structure suggested an alternative, flipped binding orientation of the new inhibitors.
Selective and facile synthesis of α,β-unsaturated nitriles and amides with N-hydroxyphthalimide as the nitrogen source
Yan, Yiyan,Xu, Xiaohe,Jie, Xiaokang,Cheng, Jingya,Bai, Renren,Shuai, Qi,Xie, Yuanyuan
supporting information, p. 2793 - 2796 (2018/06/25)
The direct conversion of α,β-unsaturated aldehydes to corresponding nitriles promoted by Pd(OAc)2 and phthalic acid which was hydrolyzed from N-hydroxyphthalimide (NHPI) has been disclosed. Additionally, it was found that when water was used as the solvent, α,β-unsaturated amides was obtained as the main products in good to excellent yields. It was first reported that NHPI was utilized as the nitrogen source to synthesize α,β-unsaturated nitriles and amides from aldehydes. Control experiment demonstrated that aldehydes undergo a process of oximation and dehydration to form nitriles and amides.
Preparation method of trans-alpha, beta-unsaturated nitriles compound
-
Paragraph 0069-0071, (2017/05/18)
The invention relates to a preparation method of a trans-alpha, beta-unsaturated nitriles compound. The method comprises the following steps: uniformly mixing a benzyl alcohol compound, acetonitrile, a promoter and alkali, and carrying out reflux reaction completely to obtain reaction liquid; carrying out conventional extraction, drying, concentration and column chromatographic separation on the reaction liquid in sequence to obtain the trans-alpha, beta-unsaturated nitriles compound. The preparation method belongs to double-component one-boiler reaction, so that conditions are relatively mild, and raw materials are easy to prepare and readily available; the operation is simple, the yield is relatively high, and greenness, environment friendliness and economy can be realized; large-scale production can be realized; the preparation method has an extremely good application potential on the aspect of fine chemicals, and has a relatively good industrial application prospect.
Cyanation of aromatic/vinylic boronic acids with α-cyanoacetates
Wang, Xian-Jin,Zhang, Song-Lin
supporting information, p. 14826 - 14830 (2017/12/15)
A friendly protocol is reported to achieve cyanation of aromatic and vinylic boronic acids using nontoxic and readily available α-cyanoacetates as a cyano source under aerobic conditions. Many aryl/vinyl boronic acids (as well as some iodides and bromides) are amenable substrates to give aryl nitriles and acrylonitriles. This cyanation method provides a safe and operationally convenient alternative to traditional ones requiring toxic cyanide salts.
In-situ-generated palladium nanoparticles in novel ionic liquid: an efficient catalytic system for Heck–Matsuda coupling
Gaikwad,Undale,Patil,Pore,Korade,Kamble
, p. 4445 - 4458 (2017/07/22)
Abstract: A green, convenient, ecological and recyclable method comprising dual functionalized, task-specific, ionic liquid (IL)-triggered, in situ-generated Pd nanoparticles (NPs) and their catalytic application for Heck–Matsuda coupling of olefins is described. Both arenediazonium tetrafluoroborate and silica sulphate salts are coupled with olefins under ligand-free and aerobic conditions at ambient temperature furnishing excellent yields of products. The Ionic liquid used acts as a reducing as well as stabilizing agent for in situ-generated Pd NPs. The formed NPs were characterized by transmission electron microscopy (TEM) analysis, having a size below 50?nm, and exhibited high catalytic activity. The catalytic system can be reused for eight times effectively without any significant loss of activity. The method was found to be highly stereo-specific, giving exclusively the ‘E’ isomer.
Associative Covalent Relay: An Oxadiazolone Strategy for Rhodium(III)-Catalyzed Synthesis of Primary Pyridinylamines
Yu, Xiaolong,Chen, Kehao,Wang, Qi,Guo, Shan,Zha, Shanke,Zhu, Jin
supporting information, p. 5222 - 5226 (2017/04/27)
A relay formalism is proposed herein for categorizing the interplay among reactants, target product, and catalytic center in transition-metal catalysis, an important factor that can dictate overall catalysis viability and efficiency. In this formalism, transition-metal catalysis can proceed by dissociative relay, associative covalent relay, and associative dative relay modes. An intriguing associative covalent relay process operates in rhodium(III)-catalyzed oxadiazolone-directed alkenyl C?H coupling with alkynes and allows efficient access to primary pyridinylamines. Although the primary pyridinylamine synthesis mechanism is posteriori rationalized, the relay formalism formulated herein can provide an important mechanistic conceptual framework for future catalyst design and reaction development.
