19472-74-3Relevant academic research and scientific papers
Divergent synthesis of CF3-substituted polycyclic skeletons based on control of activation site of acid catalysts
Yokoo, Kazuma,Mori, Keiji
, p. 6927 - 6930 (2018)
We report a divergent synthesis of CF3-substituted fused skeletons based on precise control of the activation site through the selection of acid catalysts. When trifluoromethyl ketones with an ortho-phenethyl ether group were treated with a catalytic amount of Sc(OTf)3, a hydride shift triggered C(sp3)-H bond functionalization proceeded to give CF3-substituted isochromene derivatives by selective activation of the carbonyl group. In sharp contrast, CF3-substituted bicyclo[3.3.1]nonanes were obtained exclusively via the activation of ether oxygen initiated sequential reactions (nucleophilic attack of carbonyl oxygen, and intramolecular Friedel-Crafts reaction) under strong Br?nsted acid catalysis (Tf2NH).
Rapid and Simple Access to α-(Hetero)arylacetonitriles from Gem-Difluoroalkenes
Hu, Dandan,Liu, Jiayue,Ren, Hongjun,Song, Jinyu,Zhang, Jun-Qi,Zhu, Guorong
supporting information, p. 786 - 790 (2022/01/28)
A scalable cyanation of gem-difluoroalkenes to (hetero)arylacetonitrile derivatives was developed. This strategy features mild reaction conditions, excellent yields, wide substrate scope, and broad functional group tolerance. Significantly, in this reacti
The palladium(ii)-catalyzed regioselective ortho-C-H bromination/iodination of arylacetamides with in situ generated imidic acid as the directing group: Mechanistic exploration
Jaiswal, Yogesh,Kumar, Yogesh,Kumar, Amit
, p. 6809 - 6820 (2019/07/22)
In the present study, we report the palladium(ii)-catalyzed regioselective ortho-C-H bromination/iodination of challenging arylacetamide derivatives using N-halosuccinimides as halogenating agents. Diverse arylacetamides underwent the regioselective ortho-bromination and iodination of aromatic C-H bonds in the presence of a reactive benzylic C(sp3)-H bond without installing any bulky auxiliaries via unfavorable six-membered metallacycles. Weak coordination, the use of ubiquitous primary amides for challenging C-H functionalization, the simple catalytic system and the wide substrate scope are the key features of this transformation. Further, the halogenated amide derivatives were transformed into a variety of valuable synthons. Detailed mechanistic studies revealed some interesting aspects concerning the reaction pathway. We present for the first time strong evidence for the formation of imidic acid (in situ) from primary amides under Br?nsted acid conditions that eventually aids in the stabilization of palladacycles of amide derivatives and drives regioselective C-X bond formation.
Highly diastereoselective synthesis of tetralin-fused spirooxindoles via lewis acid-catalyzed C(sp3)H bond functionalization
Machida, Mizuki,Mori, Keiji
supporting information, p. 868 - 871 (2018/07/03)
A highly diastereoselective synthesis of tetralin-fused spirooxindole derivatives was described. Treatment of benzylidene oxindoles with a catalytic amount of Sc(OTf)3 in refluxing hexane afforded the target compounds in good chemical yields with excellent diastereoselectivities (up to >20:1). Detailed investigation of the reaction mechanism revealed that both interconversion of the two diastereomers and their solubility difference in reaction medium were the key to achieving excellent diastereoselectivities.
Construction of 1,3-Dithio-Substituted Tetralins by [1,5]-Alkylthio Group Transfer Mediated Skeletal Rearrangement
Hisano, Naoya,Kamei, Yuto,Kansaku, Yaoki,Yamanaka, Masahiro,Mori, Keiji
supporting information, p. 4223 - 4226 (2018/07/29)
A novel skeletal rearrangement involving a [1,5]-alkylthio group transfer/cyclization sequence is described. Treatment of benzylidene malonates having a thioketal moiety at the homobenzyl position with a catalytic amount of Sc(OTf)3 afforded alkylthio group rearranged adducts in good chemical yields. Detailed investigation of the reaction mechanism revealed that an intramolecular conjugate addition/ring opening sequence (not through-space transfer) is the key to achieving this reaction.
Chiral Magnesium Bisphosphate-Catalyzed Asymmetric Double C(sp3)-H Bond Functionalization Based on Sequential Hydride Shift/Cyclization Process
Mori, Keiji,Isogai, Ryo,Kamei, Yuto,Yamanaka, Masahiro,Akiyama, Takahiko
supporting information, p. 6203 - 6207 (2018/05/23)
Described herein is a chiral magnesium bisphosphate-catalyzed asymmetric double C(sp3)-H bond functionalization triggered by a sequential hydride shift/cyclization process. This reaction consists of stereoselective domino C(sp3)-H bond functionalization: (1) a highly enantio- and diastereoselective C(sp3)-H bond functionalization by chiral magnesium bisphosphate (first [1,5]-hydride shift), and (2) a highly diastereoselective C(sp3)-H bond functionalization by an achiral catalyst (Yb(OTf)3, second [1,5]-hydride shift).
Palladium-Catalyzed, ortho-Selective C-H Halogenation of Benzyl Nitriles, Aryl Weinreb Amides, and Anilides
Das, Riki,Kapur, Manmohan
, p. 1114 - 1126 (2018/06/18)
A palladium-catalyzed, ortho-selective C-H halogenation methodology is reported herein. The highlight of the work is the highly selective C(sp2)-H functionalization of benzyl nitriles in the presence of activated C(sp3)-H bond, which results in good yields of the halogenated products with excellent regioselectivity. Along with benzyl nitriles, aryl Weinreb amides and anilides have been evaluated for the transformation using aprotic conditions. Mechanistic studies yield interesting aspects with respect to the pathway of the reaction and the directing group abilities.
Ionic liquid-induced conversion of methoxymethyl-protected alcohols into nitriles and iodides using [Hmim][NO3]
Noei, Jalil,Mirjafari, Arsalan
supporting information, p. 4424 - 4426 (2014/08/05)
This Letter reports a one-pot efficient conversion of methoxymethyl-ethers into their corresponding nitriles and iodides using the ionic liquid, 1-methyl-3H-imidazolium nitrate ([Hmim][NO3]) under microwave irradiation. A variety of products were prepared in high yields using this method.
Synthesis of α-aryl esters and nitriles: Deaminative coupling of α-aminoesters and α-aminoacetonitriles with arylboronic acids
Wu, Guojiao,Deng, Yifan,Wu, Chaoqiang,Zhang, Yan,Wang, Jianbo
supporting information, p. 10510 - 10514 (2016/02/18)
Transition-metal-free synthesis of α-aryl esters and nitriles using arylboronic acids with α-aminoesters and α-aminoacetonitriles, respectively, as the starting materials has been developed. The reaction represents a rare case of converting C(sp3)-N bonds into C(sp3)-C(sp2) bonds. The reaction conditions are mild, demonstrate good functional-group tolerance, and can be scaled up. Touch base: A transition-metal-free protocol for the synthesis of α-aryl esters and nitriles by deaminative coupling is presented. Strong bases and transition-metal catalysts are not needed. The new synthetic method uses readily available starting materials and demonstrates wide substrate scope.
Gold-catalyzed 1,2-oxoarylations of nitriles with pyridine-derived oxides
Karad, Somnath Narayan,Liu, Rai-Shung
supporting information, p. 5444 - 5448 (2014/06/09)
We report the first success in the gold-catalyzed oxoarylations of nitriles with pyridine-derived N-oxides using gold carbenes as initiators. These oxoarylations were also achieved satisfactorily in intermolecular three-component oxidations, including diverse alkenyldiazo esters, nitriles, and pyridine-based oxides. Spill the (car)benes: Reported herein is the first successful gold-catalyzed oxoarylation of nitriles with pyridine-derived N-oxides using gold carbenes as initiators (see scheme; DCE=1,2-dichloroethane, IPr=1,3-bis(diisopropylphenyl)imidazol-2-ylidene). These oxoarylations were also achieved satisfactorily in intermolecular three-component oxidations using a variety of alkenyldiazo esters, nitriles, and pyridine-based N-oxides.
