62501-58-0Relevant articles and documents
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.
Palladium-Catalyzed Nitrile-Assisted C(sp3)-Cl Bond Formation for Synthesis of Dichlorides
He, Dandan,Huang, Liangbin,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
, p. 8308 - 8311 (2019/10/16)
A palladium-catalyzed coupling procedure of alkenes with alkynylnitriles has been demonstrated for the synthesis of dichlorides. The reaction is the first example of nitrile-assisted C(sp3)-Cl formation promoted by coordination of a cyano group with an alkylpalladium(II) complex. The construction of a five-membered cycle intermediate successfully inhibits the β-hydride abstraction, resulting in direct C-Cl bond reductive elimination of alkylpalladium(II) chloride.
Transition Metal-Free Approach to Propynenitriles and 3-Chloropropenenitriles
Sharma, Pawan K.,Ram, Sita,Chandak, Navneet
supporting information, p. 894 - 899 (2016/04/05)
A transition metal-free, facile and efficient one-pot protocol for the synthesis of propynenitriles from readily available 3-chloropropenals is disclosed. The reaction conditions have also been optimized for the exclusive formation and isolation of 3-chloropropenenitriles which are important building blocks in general and are intermediates in the synthesis of propynenitriles. The hallmark of the methodology is the use of non-toxic reagents, milder, metal-free and economically benign reaction conditions avoiding a harsh dehydration step while achieving excellent yields.
