21983-34-6Relevant academic research and scientific papers
Gold(I)-Catalyzed Oxidative 1,4-Additions of 3-En-1-ynamide with Nitrones via Carbon- versus Nitrogen-Addition Chemoselectivity
Tanpure, Sudhakar Dattatray,Kale, Balaji S.,Liu, Rai-Shung
, p. 1394 - 1399 (2021/02/20)
This work reports gold-catalyzed 1,4-oxofunctionalizations of 3-en-1-ynamides with nitrones, yielding two distinct E-configured products. We obtained 1,4-oxoarylation products from 3-en-1-ynamides bearing C(4)-electron-donating substituents and 1,4-oxoamination products from those analogues bearing C(4)-aryl substituents. We propose that if vinylgold carbenes are stable, imines undergo a para-arylation on these gold carbenes. If vinylgold carbenes are highly electron-deficient, this N-attack is irreversible to enable 1,4-oxoaminations.
Regio- and Stereoselective N-addition to an Open Bromo Vinyl Cation
Chuchmareva, Marina,Collong, Arndt,Niggemann, Meike,Schr?der, Sebastian,Strauch, Christina
supporting information, (2021/06/07)
A protocol for the synthesis of thus far inaccessible bromo vinyl triflimides is presented. Our previously reported concept of assisted vinyl cation formation was engaged to achieve both a protonation of relatively electron poor bromo alkynes and a reaction with high regio- and stereoselectivity. To the best of our knowledge, this is the first stereoselective addition of an N-nucleophile to an open β-halovinyl cation.
Dual Gold-Catalyzed Formal Tetradehydro-Diels–Alder Reactions for the Synthesis of Carbazoles and Indolines
Wang, Hong-Fa,Wang, Shi-Yue,Qin, Tian-Zhu,Zi, Weiwei
, p. 17911 - 17914 (2018/11/23)
This work reports a dual gold-catalyzed tetradehydro-Diels–Alder reaction for the synthesis of nitrogen-containing aromatic heterocycles. Under the catalytic system (IPrAuNTf2/DIPEA), indolines and carbazoles as well as other N-containing aromatic heterocycles were prepared in high yields with good functional group tolerance. Unlike the traditional thermal tetradehydro-Diels–Alder reactions, diluted reaction concentration and radical prohibitors are not required for this protocol. Experimental data support a mechanism involving gold vinylidene species, which undergoes a 6 π electrocyclization, followed with 1,2-hydrogen shift.
Borane-catalyzed selective hydrosilylation of internal ynamides leading to β-silyl (Z)-enamides
Kim, Youngchan,Dateer, Ramesh B.,Chang, Sukbok
supporting information, p. 190 - 193 (2017/11/27)
We have developed a borane-catalyzed regioand stereoselective hydrosilylation of internal ynamides for the first time. The scope of ynamide substrates and silane reactants was broad under mild reaction conditions, affording synthetically versatile β-silyl (Z)-enamide products. The observed stereoselectivity was reasoned to be due to the β-silicon effect on a postulated ketene iminium intermediate.
Gold-Catalyzed Intermolecular Ynamide Amination-Initiated Aza-Nazarov Cyclization: Access to Functionalized 2-Aminopyrroles
Shu, Chao,Wang, Yong-Heng,Shen, Cang-Hai,Ruan, Peng-Peng,Lu, Xin,Ye, Long-Wu
supporting information, p. 3254 - 3257 (2016/07/13)
A novel gold-catalyzed intermolecular ynamide amination-initiated aza-Nazarov cyclization has been developed, allowing the facile and efficient synthesis of various 2-aminopyrroles in moderate to good yields. Furthermore, a mechanistic rationale for this
Zinc-Catalyzed Stereo- and Regioselective 1,4-Hydrative Fluorination of 3-En-1-ynamides with Selectfluor
Jadhav, Appaso Mahadev,Huple, Deepak B.,Singh, Rahulkumar Rajmani,Liu, Rai Shung
supporting information, p. 1017 - 1022 (2016/04/19)
Zinc-catalyzed 1,4-oxofluorinations of 3-en-1-ynamides with Selectfluor in acetonitrile/water proceeded with high regio- and stereoselectivity, giving E-configured γ-fluoro-α,β-unsaturated amides efficiently. Our control experiments indicate that kinetica
Palladium-Catalyzed Regioselective Alkynylation of Pyrroles and Azoles under Mild Conditions: Application to the Synthesis of a Dopamine D-4 Receptor Agonist
Brachet, Etienne,Belmont, Philippe
, p. 7519 - 7529 (2015/08/18)
A mild and general method for the direct alkynylation of azoles such as pyrrole, indole, and 7-azaindole is described here. Using a simple catalytic system such as Pd(OAc)2 (2.5 mol %), P(tBu)2Me·HBF4 (5 mol %), and NaOAc (2 equiv) allowed the regioselective introduction of various alkynyl residues at the C-2 position of pyrroles. Interestingly, C-2 alkynylation was also observed on C-3-substituted indoles, whereas classical C-3 alkynylation was obtained on selected unsubstituted indoles and 7-azaindole. Our methodology has been illustrated by the efficient synthesis of a potential schizophrenia drug (dopamine D-4 inhibitor).
ZnII- and AuI-catalyzed regioselective hydrative oxidations of 3-En-1-ynes with selectfluor: Realization of 1,4-dioxo and 1,4-oxohydroxy functionalizations
Jadhav, Appaso Mahadev,Gawade, Sagar Ashok,Vasu, Dhananjayan,Dateer, Ramesh B.,Liu, Rai-Shung
, p. 1813 - 1817 (2014/03/21)
Catalytic 1,4-dioxo functionalizations of 3-en-1-ynes to (Z)- and (E)-2-en-1,4-dicarbonyl compounds are described. This regioselective difunctionalization was achieved in one-pot operation through initial alkyne hydration followed by in situ Selectfluor oxidation. The presence of pyridine alters the reaction chemoselectivity to give 4-hydroxy-2-en-1-carbonyl products instead. A cooperative action of pyridine and ZnII assists the hydrolysis of key oxonium intermediate.
Facile and efficient synthesis of 1-haloalkynes via DBU-mediated reaction of terminal alkynes and N-haloimides under mild conditions
Li, Mengru,Li, Yueju,Zhao, Baozhong,Liang, Fushun,Jin, Long-Yi
, p. 30046 - 30049 (2014/08/05)
Directly from terminal alkynes and with N-halosuccinimides (halo = Br and I) or N-cholorophthalimide as the halogen sources, DBU as the activator, 1-haloalkynes were prepared in good to excellent yields at room temperature. Bis(bromoalkyne) and bis(iodoal
