214907-24-1Relevant articles and documents
Cu-catalyzed [2 + 2 + 1] cascade annulation of vinyl iodonium salts with elemental sulfur/selenium for the modular synthesis of thiophenes and selenophenes
Chen, Chao,Wang, Fei,Wu, Chao,Wu, Yaxing
supporting information, p. 945 - 949 (2022/02/01)
A [2 + 2 + 1] annulation protocol has been established for the modular synthesis of 2,4-disubstituted thiophenes/selenophenes, with excellent regioselectivity. The reactions have been catalyzed by copper salt with elemental sulfur and selenium serving as
Synthesis of Acrylonitriles via Mild Base Promoted Tandem Nucleophilic Substitution-Isomerization of α-Cyanohydrin Methanesulfonates
Liu, Shiwen,Meng, Lingling,Zeng, Xiaojun,Hammond, Gerald B.,Xu, Bo
, p. 913 - 917 (2021/04/05)
Main observation and conclusion: We have developed an efficient synthesis of acrylonitriles via mild base promoted tandem nucleophilic substitution-isomerization of α-cyanohydrin methanesulfonates with alkenylboronic acids. This transition metal-free protocol works under simple and mild conditions and offers good chemical yields for a wide range of substrates and demonstrates good functional group tolerance. (Figure presented.).
Transition-Metal-Free C(sp2)–C(sp2) Cross-Coupling of Diazo Quinones with Catechol Boronic Esters
Che, Chi-Ming,Wu, Kai,Wu, Liang-Liang,Zhou, Cong-Ying
supporting information, p. 16202 - 16208 (2020/07/17)
A transition-metal-free C(sp2)?C(sp2) bond formation reaction by the cross-coupling of diazo quinones with catechol boronic esters was developed. With this protocol, a variety of biaryls and alkenyl phenols were obtained in good to high yields under mild conditions. The reaction tolerates various functionalities and is applicable to the derivatization of pharmaceuticals and natural products. The synthetic utility of the method was demonstrated by the short synthesis of multi-substituted triphenylenes and three bioactive natural products, honokiol, moracin M, and stemofuran A. Mechanistic studies and density functional theory (DFT) calculations revealed that the reaction involves attack of the boronic ester by a singlet quinone carbene followed by a 1,2-rearrangement through a stepwise mechanism.
Synthesis of α-Borylated Ketones by Regioselective Wacker Oxidation of Alkenylboronates
Corless, Victoria B.,Holownia, Aleksandra,Foy, Hayden,Mendoza-Sanchez, Rodrigo,Adachi, Shinya,Dudding, Travis,Yudin, Andrei K.
supporting information, p. 5300 - 5303 (2018/09/12)
As part of a program aimed at metal-catalyzed oxidative transformations of molecules with carbon-metalloid bonds, the synthesis of α-borylated ketones is reported via regioselective TBHP-mediated Wacker-type oxidation of N-methyliminodiacetic acid (MIDA)-protected alkenylboronates. The observed regioselectivity correlates with the hemilabile nature of the B-N dative bond in the MIDA boronate functional group, which allows boron to guide selectivity through a neighboring group effect.
Oxalyl Boronates Enable Modular Synthesis of Bioactive Imidazoles
Lee, C. Frank,Holownia, Aleksandra,Bennett, James M.,Elkins, Jonathan M.,St. Denis, Jeffrey D.,Adachi, Shinya,Yudin, Andrei K.
supporting information, p. 6264 - 6267 (2017/05/19)
Described herein is the preparation of oxalyl boronate building blocks and their application for the construction of heterocycles. The oxalyl unit, readily accessible through commercially available starting materials, enables a modular approach for the synthesis of imidazoles. A variety of aromatic, heteroaromatic, and alkyl carboxaldehydes were condensed with oxalyl boronates to afford substituted boryl imidazoles in a regiocontrolled fashion. Subsequent palladium-catalyzed cross-coupling with haloarenes furnished the desired trisubstituted imidazole scaffolds. To demonstrate the utility of these scaffolds, potent inhibitors of the serine/threonine-protein kinase STK10 were synthesized.
Copper-Catalyzed [2+2+2] Modular Synthesis of Multisubstituted Pyridines: Alkenylation of Nitriles with Vinyliodonium Salts
Sheng, Jinyu,Wang, Yong,Su, Xiang,He, Ru,Chen, Chao
supporting information, p. 4824 - 4828 (2017/04/11)
A [2+2+2] modular synthesis of multisubstituted pyridines, with excellent regioselectivity, has been realized by copper catalysisand involves three distinct components: vinyliodonium salts, nitriles, and alkynes. The reactions proceeded with the facile formation of an aza-butadienylium intermediate by alkenylation of the nitrile with a vinyliodonium salt. Moreover, the alkynes in the reaction were extended to alkenes, which are an advantage of expense and relative scarceness of alkynes.
Highly enantioselective Rh-Catalyzed Alkenylation of imines: Synthesis of Chiral Allylic Amines via Asymmetric addition of Potassium Alkenyltrifluoroborates to N-Tosyl imines
Gopula, Balraj,Chiang, Chien-Wei,Lee, Way-Zen,Kuo, Ting-Shen,Wu, Ping-Yu,Henschke, Julian P.,Wu, Hsyueh-Liang
supporting information, p. 632 - 635 (2014/04/03)
For the first time, simple N-tosyl aryl aldimines, prepared from the condensation of tosyl amide and aromatic aldehydes, can be used as substrates in the rhodium catalyzed 1,2- addition reaction using alkenylboron nucleophiles. In the presence of 1.5 mol % of [RhCl(1e)]2, enantioselective addition of various potassium alkenyltrifluoroborates to aryl aldimines furnished the corresponding chiral allylic amines in 73-96% yield and 72->99.5% ee. Notably, this method efficiently provides the di-, tri-, and tetrasubstituted allylic N-tosyl amines with high asymmetric induction.
