28144-67-4Relevant academic research and scientific papers
Nucleophilic Alkoxylations of Unactivated Alkyl Olefins and α-Methyl Styrene by Photoredox Catalysis
Seyfert, Fabienne,Mitha, Mathis,Wagenknecht, Hans-Achim
, p. 773 - 776 (2021/01/12)
N,N-diisobutylaminophenyl-phenothiazine is a strongly reducing catalyst that allows – for the first time – the photoredox catalytic addition of alcohols to alkyl olefins as non-activated substrates to products with Markovnikov orientation. The irradiation at 365 nm does not require any additional reagent. Using α-methyl styrene as activated substrate we additionally show that this photoredox catalytic method tolerates other functional groups, including allyl, alkynyl, cyanide, and even acid-labile Boc groups within the substrate scope.
The cascade coupling/iodoaminocyclization reaction of trifluoroacetimidoyl chlorides and allylamines: metal-free access to 2-trifluoromethyl-imidazolines
Chen, Zhengkai,Du, Shiying,Song, Yufei,Wang, Le-Cheng,Wu, Xiao-Feng
, p. 6115 - 6119 (2021/07/21)
A metal-free cascade coupling/iodoaminocyclization reaction for the rapid assembly of 2-trifluoromethyl-imidazolines has been disclosed. The transformation applies readily accessible trifluoroacetimidoyl chlorides, allylamines andN-iodosuccinimides as the starting substrates, achieving an efficient and straightforward pathway to construct diverse imidazoline derivatives. Excellent efficiency of the reaction is observed (higher than 90% isolated yield for half of the examples), and the obtained imidazoline products bearing a pendent iodomethyl group could be easily transformed into other synthetically valuable compounds.
Visible-light-promoted radical alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester: Synthesis of oxazolines
Ding, Hao,Huang, Panyi,Jin, Can,Su, Weike,Sun, Bin,Yan, Zhiyang,Zhao, Haiyun
, (2021/10/29)
An efficient photocatalytic alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester has been developed. The transformation is taken advantage of alkyl radicals to attack allylic amide with the assist of inexpensive rose bengal as photocatalyst to prepare a series of alkyl substituted oxazolines in moderate to excellent yields. High regioselectivity, operational safety, mild conditions and excellent substrate generality give this protocol broad application prospects.
Chiral selenide-catalyzed enantioselective synthesis of trifluoromethylthiolated 2,5-disubstituted oxazolines
Qin, Tian,Jiang, Quanbin,Ji, Jieying,Luo, Jie,Zhao, Xiaodan
, p. 1763 - 1766 (2019/02/20)
Chiral selenide-catalyzed enantioselective trifluoromethylthiolation of 1,1-disubstituted alkenes is disclosed. By this method, a variety of chiral trifluoromethylthiolated 2,5-disubstituted oxazolines were obtained in good yields with high enantioselectivities. This work not only provides a new pathway for the synthesis of chiral oxazolines, but also expands the library of chiral trifluoromethylthiolated molecules.
Catalytic Geminal Difluorination of Styrenes for the Construction of Fluorine-rich Bioisosteres
Scheidt, Felix,Neufeld, Jessica,Sch?fer, Michael,Thiehoff, Christian,Gilmour, Ryan
, p. 8073 - 8076 (2019/01/04)
A geminal difluorination of alkenes based on I(I)/I(III) catalysis is disclosed, which is compatible with a range of electronically and substitutionally diverse styrenes (27 examples, up to 89% yield). Employing inexpensive p-TolI as the organocatalyst, turnover is enabled by Selectfluor-mediated oxidation to generate the ArIF2 species in situ. Extension to include α-substituted styrenes bearing fluorine-containing groups is disclosed and provides an expansive platform for the generation of fluorine-rich architectures.
Flavin-Mediated Visible-Light [2+2] Photocycloaddition of Nitrogen- and Sulfur-Containing Dienes
Jirásek, Michael,Straková, Karolína,Nevesely, Tomá?,Svobodová, Eva,Rottnerová, Zdeňka,Cibulka, Radek
, p. 2139 - 2146 (2017/04/24)
The [2+2] photocycloaddition mediated by 1-butyl-3-methyl-7,8-dimethoxyalloxazine (1) has been found to be an effective tool for cyclising ω-phenyl- and ω,ω′-diphenyl-4-aza-1,6-heptadienes, in which the nitrogen atom is protected by acylation or quaternisation, towards the synthesis of a variety of phenyl- and diphenyl-3-azabicyclo[3.2.0]heptanes and their corresponding quaternary salts. Thia derivatives, with the sulfur atom in the form of a sulfone group, underwent an analogous cyclisation. Advantageously, visible light (400 nm) was used for the cycloadditions in the presence of 1, in contrast to the previously described procedures affording azabicyclo[3.2.0]heptanes by using UV irradiation. Practical applications are demonstrated through the synthesis of bicyclic quaternary ammonium salts, 6-phenyl-azabicyclo[3.2.0]heptanes known to exhibit biological activity or chiral spiro ammonium salts. Flavin 1 was also found to promote the efficient E→Z isomerisation of electron-rich cinnamyl derivatives to produce mixtures enriched with the Z isomer (with Z/E ratios of up to 77:23).
Conformationally restricted pyrrolidines by intramolecular [2+2] photocycloaddition reactions
Fort, Diego A.,Woltering, Thomas J.,Nettekoven, Matthias,Knust, Henner,Bach, Thorsten
, p. 2989 - 2991 (2013/05/09)
Intramolecular [2+2] photocycloaddition reactions of diversely substituted N-Boc protected 4-(allylaminomethyl)-2(5H)-furanones resulted in rigid products (53-75%) with three spatially defined positions for further functionalisation. The Royal Society of Chemistry.
Solvent-dependent enantiodivergence in the chlorocyclization of unsaturated carbamates
Garzan, Atefeh,Jaganathan, Arvind,Salehi Marzijarani, Nastaran,Yousefi, Roozbeh,Whitehead, Daniel C.,Jackson, James E.,Borhan, Babak
, p. 9015 - 9021 (2013/07/26)
A remarkable solvent-controlled enantiodivergence is seen in the hydroquinidine 1,4-phthalazinediyl diether ((DHQD)2PHAL)-catalyzed chlorocyclization of unsaturated carbamates. Eyring plot analyses of this previously unreported reaction are used to probe and compare the R- and S-selective pathways. In the CHCl3/hexanes solvent system, the pro-R process shows a surprising increase in selectivity with increasing temperature. These studies point to a strongly solvent-dependent entropy-enthalpy balance between the pro-R and pro-S pathways. Two solvents, two enantiomers: Enantiodivergent hydroquinidine 1,4-phthalazinediyl diether ((DHQD) 2PHAL)-catalyzed chlorocyclization of unsaturated carbamates, controlled solely by the choice of solvent, yields oxazolidinones in high enantioselectivity (see scheme; DCDMH=1,3-dichloro-5,5-dimethyl hydantoin). The origin of the observed enantiodivergence is traced back to a solvent-selected entropy-enthalpy balance between pro-R and pro-S pathways that dictates the course of the reaction. Copyright
Asymmetric hydrogenation of protected allylic amines
Steinhuebel, Dietrich P.,Krska, Shane W.,Alorati, Anthony,Baxter, Jenny M.,Belyk, Kevin,Bishop, Brian,Palucki, Michael,Sun, Yongkui,Davies, Ian W.
supporting information; experimental part, p. 4201 - 4203 (2010/11/19)
A general method for the enantioselective hydrogenation of protected allylic amine derivatives is described. This procedure relies on the generation of a cationic ruthenium complex with the axially chiral ligand (-)-TMBTP. The utility is highlighted by th
Copper-catalyzed allylic hydroxyamination and amination of alkenes with Boc-hydroxylamine
Kalita, Biswajit,Nicholas, Kenneth M.
, p. 1451 - 1453 (2007/10/03)
Olefins react regioselectively with Boc-NHOH in the presence of Cu(I,II) salts to produce allyl-N(OH)(Boc) derivatives, apparently via the intermediacy of Boc-NO; yields and rates are dramatically improved by the addition of H 2O2. The corresponding allylamine derivatives, allyl-NH(Boc), are formed selectively from Boc-NHOH/olefin with CuBr/P(OEt) 3.
