18756-03-1Relevant academic research and scientific papers
Study on the stereoselective reactions of vinyl(phenyl)iodonium salts with sodium selenide, sodium sulfide, sodium azide and potassium thiocyanate
Yan, Jie,Jin, Hongwei,Chen, Zhenchu
, p. 233 - 235 (2007)
The reactions of vinyl(phenyl)iodonium salts with sodium selenide, sodium sulfide, sodium azide and potassium thiocyanate have been studied. Divinylic selenides, divinylic sulfides, vinylic azides and vinylic thiocyanates were synthesised stereoselectivel
New simple syntheses of (E)-1-azido- (or thiocyanato)-alk-1-enes from alk-1-ynes by hydroboration
Masuda, Yuzuru,Murata, Miki,Ikeda, Minehito,Watanabe, Shinji
, p. 1013 - 1014 (1998)
Stereochemically pure (E)-1-azido- (or thiocyanato)-alk-1-enes have been synthesized in situ and in reasonable yields from alk-1-ynes upon hydroboration with disiamylborane followed by reactions with simple reagents; sodium azide (or potassium thiocyanate
Regioselective ring opening of silyl epoxy alcohols with azide ion
Chakraborty,Reddy
, p. 1335 - 1338 (1990)
Presence of silyl group on epoxy ring allows azide ion to open 2,3-epoxy alcohols exclusively at the silicon bearing carbon.
Ring Enlargement of Three-Membered Heterocycles by Treatment with In Situ Formed Tricyanomethane
Banert, Klaus,Chityala, Madhu,Korb, Marcus
supporting information, p. 6158 - 6164 (2020/05/04)
Although the chemistry of elusive tricyanomethane (cyanoform) has been studied during a period of more than 150 years, this compound has very rarely been utilized in the synthesis or modification of heterocycles. Three-membered heterocycles, such as epoxides, thiirane, aziridines, or 2H-azirines, are now treated with tricyanomethane, which is generated in situ by heating azidomethylidene-malonodinitrile in tetrahydrofuran at 45 °C or by adding sulfuric acid to potassium tricyanomethanide. This leads to ring expansion with formation of 2-(dicyanomethylidene)oxazolidine derivatives or creation of the corresponding thiazolidine, imidazolidine, or imidazoline compounds and opens up a new access to these push–pull-substituted olefinic products. The regio- and stereochemistry of the ring-enlargement processes are discussed, and the proposed reaction mechanisms were confirmed by using 15N-labeled substrates. It turns out that different mechanisms are operating; however, tricyanomethanide is always acting as a nitrogen-centered nucleophile, which is quite unusual if compared to other reactions of this species.
Practical Solvent-Free Microwave-Assisted Hydroboration of Alkynes
Altarejos, Julia,Sucunza, David,Vaquero, Juan J.,Carreras, Javier
, p. 3024 - 3029 (2020/05/18)
A simple and rapid protocol for the anti-Markovnikov hydroboration of alkynes assisted by microwave irradiation has been developed. Pinacolborane smoothly reacts with terminal alkynes to obtain (E)-alkenyl boronates in good yields and short reactions times in the absence of solvent. Further transformations on the carbon-boron bond of the adducts can be sequentially achieved without the need of purifying the alkenyl boronates.
Rhodium-Catalyzed Deoxygenation and Borylation of Ketones: A Combined Experimental and Theoretical Investigation
Tao, Lei,Guo, Xueying,Li, Jie,Li, Ruoling,Lin, Zhenyang,Zhao, Wanxiang
, p. 18118 - 18127 (2020/11/26)
The rhodium-catalyzed deoxygenation and borylation of ketones with B2pin2 have been developed, leading to efficient formation of alkenes, vinylboronates, and vinyldiboronates. These reactions feature mild reaction conditions, a broad substrate scope, and excellent functional-group compatibility. Mechanistic studies support that the ketones initially undergo a Rh-catalyzed deoxygenation to give alkenes via boron enolate intermediates, and the subsequent Rh-catalyzed dehydrogenative borylation of alkenes leads to the formation of vinylboronates and diboration products, which is also supported by density functional theory calculations.
Catalyst-free and solvent-free hydroboration of alkynes
Jaladi, Ashok Kumar,Choi, Hyeon Seong,An, Duk Keun
, p. 13626 - 13632 (2020/09/07)
The hydroboration of alkynes with pinacolborane (HBpin) under catalyst- and solvent-free conditions was demonstrated. Various alkynes were smoothly converted into alkenyl boronate esters in good to excellent yields at 110 °C. The gram-scale hydroboration
Chan-Lam-type Azidation and One-Pot CuAAC under CuI-Zeolite Catalysis
Clerc, Arnaud,Bénéteau, Valérie,Pale, Patrick,Chassaing, Stefan
, p. 2060 - 2065 (2020/03/03)
The copper(I)-exchanged zeolite CuI-USY proved to efficiently catalyze the direct azidation of arylboronic acids with sodium azide under simple and practical conditions, namely at room temperature under air with methanol as solvent and without any additive. This easy-to-prepare and cheap catalytic material has been demonstrated to be recyclable and the mild azidation conditions further showed good functional-group tolerance, leading to a variety of substituted (hetero)aryl azides (18 examples). Interestingly, the azidation reaction has been successfully coupled to a CuAAC reaction, thus allowing access to triazoles from arylboronic acids via a one-pot CuI-catalyzed process.
Stereoselective Synthesis of Vinylboronates by Rh-Catalyzed Borylation of Stereoisomeric Mixtures
Li, Shenhuan,Li, Jie,Xia, Tianlai,Zhao, Wanxiang
, p. 462 - 468 (2019/03/28)
The stereoselective preparation of vinylboronates via rhodium-catalyzed borylation of E/Z mixtures of vinyl actetates is described, and this method was also extended to synthesis of vinyldiboronates. These transformations feature high functional group compatibility and mild reaction conditions. Control experiments support a mechanism that involved a Rh-catalyzed borylation-isomerization sequence. The isomerization of (Z)-vinylboronates to (E)-isomers was also demonstrated.
AgSbF6-Catalyzed: Anti -Markovnikov hydroboration of terminal alkynes
Mamidala, Ramesh,Pandey, Vipin K.,Rit, Arnab
, p. 989 - 992 (2019/01/23)
AgSbF6-Catalyzed anti-Markovnikov addition of pinacolborane (HBpin) to terminal alkynes to produce the E-vinylboronates is reported. This efficient methodology is scalable, compatible with sterically and electronically diverse alkynes, and works at room temperature under solvent-free condition. The utility of this method is demonstrated in the facile synthesis of the clinically important (E)-2,4,3′,5′-tetramethoxystilbene.
