305837-95-0Relevant academic research and scientific papers
Enantioselective Nickel-Catalyzed anti-Arylmetallative Cyclizations onto Acyclic Ketones
Green, Harley,Argent, Stephen P.,Lam, Hon Wai
supporting information, p. 5897 - 5900 (2021/03/16)
Domino reactions involving nickel-catalyzed additions of (hetero)arylboronic acids to alkynes, followed by cyclization of the alkenylnickel intermediates onto tethered acyclic ketones to give chiral tertiary-alcohol-containing products in high enantioselectivities, are described. The reversible E/Z isomerization of the alkenylnickel intermediates enables overall anti-arylmetallative cyclization to occur. The ring system of the products are substructures of certain diarylindolizidine alkaloids.
Nickel-catalyzed asymmetric arylative cyclization of N-alkynones: Efficient access to 1,2,3,6-tetrahydropyridines with a tertiary alcohol
Tian, Jiangyan,Li, Wendian,Li, Ruihao,He, Lin,Lv, Hui
, p. 4038 - 4040 (2021/07/06)
Nickel/(S)-t-Bu-PHOX complex catalyzed asymmetric arylative cyclization of N-alkynones has been achieved, delivering 1,2,3,6-tetrahydropyridines containing a chiral tertiary alcohol in high yields and excellent enantioselectivities, which provides efficient access to chiral tetrahydropyridine and piperidine analogues.
Ru(II)-Catalyzed Regioselective Hydroarylative Coupling of Indolines with Internal Alkynes by C?H Activation
Ahmad, Ashfaq,Ampapathi, Ravi Sankar,Dutta, Himangsu Sekhar,Kant, Ruchir,Khan, Afsar Ali,Koley, Dipankar,Kumar, Mohit,Raziullah,Vaishnav, Jayanti
supporting information, p. 2107 - 2113 (2021/07/22)
We have developed a regioselective hydroarylative coupling of indolines with internal alkynes by the activation of C?H bond using inexpensive Ru(II)-catalyst. This redox-neutral, atom-economical, and scalable C?H functionalization has been accomplished using easily removable weakly coordinating directing group. Diverse unsymmetrically substituted alkynes appended with pharmacologically important heterocycles were coupled with various indolines and 1,2,3,4-tetrahydroquinolines to furnish the corresponding trisubstituted alkenes with very high regioselectivity. The application of the method has been demonstrated with a number of alkyne-containing drug molecules, natural products, carbohydrates, amino acids, steroids, and other heterocycles. Preliminary mechanistic interrogation revealed that the C?H activation proceeds through base-assisted internal electrophilic-type substitution process.
An unconventional sulfur-to-selenium-to-carbon radical transfer: Chemo-and regioselective cyclization of yne-ynamides
Dutta, Shubham,Prabagar,Vanjari, Rajeshwer,Gandon, Vincent,Sahoo, Akhila K.
, p. 1113 - 1118 (2020/03/11)
An uncommon sulfur → selenium → carbon radical transfer process is employed to develop an unprecedented selenyl radical-mediated regioselective cyclization of yne-tethered-ynamides. Density functional theory studies and HRMS experiments are used to establish a reactivity scale between thiyl and selenyl radicals. The unique features of this transformation include, (1) the chemoselective reactivity of RSe over RS, (2) regioselective RSe attack on alkyne over ynamide, (3) 5-exo-dig cyclization of yne-ynamide to unusual 4-selenyl-pyrroles, and (4) the green synthetic method. The reaction of methyldiselenide with yne-ynamides to methylselenopyrroles is also described.
Cu(I)-catalyzed oxidative cyclization of enynamides: Regioselective access to cyclopentadiene frameworks and 2-aminofurans
Shen, Wen-Bo,Tang, Xiang-Ting,Zhang, Ting-Ting,Liu, Si-Yu,He, Jiang-Man,Su, Tong-Fu
, p. 6799 - 6804 (2020/09/15)
An efficient Cu(I)-catalyzed oxidative cyclization of alkynyl-tethered enynamides for the construction of fused bicyclic cyclopentadiene derivatives is disclosed. The cascade proceeds through alkyne oxidation, carbene/alkyne metathesis, and formal (3 + 2)
Alkyne Versus Ynamide Reactivity: Regioselective Radical Cyclization of Yne-Ynamides
Dutta, Shubham,Mallick, Rajendra K.,Prasad, Rangu,Gandon, Vincent,Sahoo, Akhila K.
, p. 2289 - 2294 (2019/01/25)
Ynamides are typically more reactive than simple alkynes and olefins. However, a serendipitous observation revealed a rare case where the reactivity of simple alkynes exceeds that of ynamides. This led to the development of a unique sulfur-radical-triggered cyclization of yne-tethered ynamides, which involves attack of the alkyne by a thiyl radical followed by cyclization with the ynamide. A wide range of novel 4-thioaryl pyrroles that could tolerate common functional moieties and N-protecting groups were expediently constructed by this strategy. The current method contrasts with the typical cyclization of yne-ynamides, which involves the attack of the alkyne moiety by the ynamide core. Control experiments and DFT calculations supported the participation of the sulfur radical in the reaction and the regioselective cyclization. The synthetic potential of the substituted pyrroles is also discussed.
Arene Trifunctionalization with Highly Fused Ring Systems through a Domino Aryne Nucleophilic and Diels–Alder Cascade
He, Jia,Jia, Zizi,Tan, Hongcheng,Luo, Xiaohua,Qiu, Dachuan,Shi, Jiarong,Xu, Hai,Li, Yang
supporting information, p. 18513 - 18518 (2019/11/19)
A convenient and efficient domino aryne process was developed under transition-metal-free conditions to generate a range of tetra- and pentacyclic ring systems. This transformation was realized via a 1,2-benzdiyne through a nucleophilic and Diels–Alder reaction cascade using styrene as the diene moiety. Three new chemical bonds, namely one C?N and two C?C bonds, and two benzofused rings could be constructed concomitantly, which was made possible by distinct chemoselective control at both the 1,2-aryne and 2,3-aryne stages. Moreover, in-depth studies were carried out on the domino aryne precursors and controlling the diastereoselectivity.
Chiral diphosphine ligand, preparation method, intermediate and application thereof
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Paragraph 0177-0181, (2019/02/13)
The invention discloses a chiral diphosphine ligand, a preparation method, an intermediate and application thereof. The structure of the chiral diphosphine ligand is shown as formula I. Compared withthe phosphine ligands in the prior art, the chiral dipho
NaBArF4-Catalyzed Oxidative Cyclization of 1,5- and 1,6-Diynes: Efficient and Divergent Synthesis of Functionalized γ- and δ-Lactams
Zhu, Bo-Han,Wang, Cai-Ming,Su, Hong-Yu,Ye, Long-Wu
supporting information, p. 58 - 62 (2019/01/04)
An efficient NaBArF4-catalyzed oxidative cyclization of readily available 1,5- and 1,6-diynes has been developed. Importantly, this transition metal-free oxidative catalysis proceeds via a presumable Lewis acid-catalyzed SN2’ pathway, which is distinct from the relevant oxidative rhodium and gold catalysis. This method leads to the facile and practical construction of a diverse range of synthetically useful γ- and δ-lactams in mostly good to excellent yields with broad substrate scope.
Gold-Catalyzed Annulations of N-Propargyl Ynamides with Anthranils with Two Distinct Chemoselectivities
Hsu, Yu-Chen,Hsieh, Shu-An,Liu, Rai-Shung
, p. 5288 - 5297 (2019/03/26)
Gold-catalyzed annulation of N-propargyl ynamides with anthranils can proceed by two distinct mechanisms. In the case of a terminal N-propargyl ynamide, its resulting α-imino gold carbene reacts with a tethered alkyne to generate a vinyl cation to enable hydrolysis, which ultimately yields a pyrrolo[2,3-b]quinoline derivative after treatment with p-toluenesulfonic acid. For an internal alkyne, its α-imino gold carbene reacts with a tethered alkyne via either a vinyl cation or an alkenylgold carbene; both paths ultimately lead to a 4-ketone-2-aminopyrrole derivative. Our mechanistic analysis indicates that water is a better nucleophile than anthranil for terminal ynamides, whereas water and anthranils are equally reactive for internal ynamides.
