33155-60-1Relevant academic research and scientific papers
Erratum: Oxazaborolidinium Ion-Catalyzed Cyclopropanation of α-Substituted Acroleins: Enantioselective Synthesis of Cyclopropanes Bearing Two Chiral Quaternary Centers (J. Am. Chem. Soc. (2011) 133:51 (20708?20711) DOI: 10.1021/ja209270e)
Gao, Lizhu,Hwang, Geum-Sook,Ryu, Do Hyun
supporting information, p. 6021 - 6022 (2021/05/13)
Pages 20709 and 20710. In the published version of the paper, the trans:cis ratios of 2w and 2x were reversed. The revised results were confirmed by NOE experiments and comparison of the optical rotation data with reported values after transformation. The
Synthesis of Rhodium Complexes with Chiral Diene Ligands via Diastereoselective Coordination and Their Application in the Asymmetric Insertion of Diazo Compounds into E?H Bonds
Ankudinov, Nikita M.,Chusov, Denis A.,Nelyubina, Yulia V.,Perekalin, Dmitry S.
supporting information, p. 18712 - 18720 (2021/07/20)
A new method for the synthesis of chiral diene rhodium catalysts is introduced. The readily available racemic tetrafluorobenzobarrelene complexes [(R2-TFB)RhCl]2 were separated into two enantiomers via selective coordination of one of them with the auxiliary S-salicyl-oxazoline ligand. One of the resulting chiral complexes with an exceptionally bulky diene ligand [(R,R-iPr2-TFB)RhCl]2 was an efficient catalyst for the asymmetric insertion of diazoesters into B?H and Si?H bonds giving the functionalized organoboranes and silanes with high yields (79–97 %) and enantiomeric purity (87–98 % ee). The stereoselectivity of separation via auxiliary ligand and that of the catalytic reaction was predicted by DFT calculations.
Catalytic Asymmetric Darzens-Type Epoxidation of Diazoesters: Highly Enantioselective Synthesis of Trisubstituted Epoxides
Jeong, Hye-Min,Nam, Dong Guk,Ryu, Do Hyun,Shim, Su Yong
supporting information, p. 22236 - 22240 (2021/09/13)
Highly enantioselective Darzens-type epoxidation of diazoesters with glyoxal derivatives was accomplished using a chiral boron–Lewis acid catalyst, which facilitated asymmetric synthesis of trisubstituted α,β-epoxy esters. In the presence of a chiral oxazaborolidinium ion catalyst, the reaction proceeded in high yield (up to 99 %) with excellent enantio- and diastereoselectivity (up to >99 % ee and >20:1 dr, respectively). The synthetic potential of this method was illustrated by conversion of the products to various compounds such as epoxy γ-butyrolactone, tertiary β-hydroxy ketone and epoxy diester.
Cu(I)/chiral bisoxazoline-catalyzed enantioselective sommelet-hauser rearrangement of sulfonium ylides
Wang, Jianbo,Li, Shu-Sen
supporting information, p. 12343 - 12358 (2020/11/10)
Catalytic asymmetric thia-Sommelet-Hauser rearrangement of sulfonium ylides remains a great challenge due to its multistep reaction mechanism involving metal carbene formation, proton transfer, and [2,3]-sigmatropic rearrangement. In particular, the key problem of such reactions is the differentiation of the enantiotopic lone pair electrons of sulfur, which generates the sulfonium ylide intermediate bearing chirality on the sulfur atom. With a modified chiral bisoxazoline ligand, we developed a Cu(I)- catalyzed asymmetric thia-Sommelet-Hauser rearrangement with good to excellent enantioselectivities. Mechanistic studies provide insights into the details of the reaction mechanism.
Catalytic Asymmetric Fluorination of Copper Carbene Complexes: Preparative Advances and a Mechanistic Rationale
Buchsteiner, Michael,Fürstner, Alois,Jerabek, Paul,Lehmann, Christian W.,Martinez-Rodriguez, Luis,N?thling, Nils,Patzer, Michael,Pozo, Iago
supporting information, p. 2509 - 2515 (2020/02/26)
The Cu-catalyzed reaction of substituted α-diazoesters with fluoride gives α-fluoroesters with ee values of up to 95 %, provided that chiral indane-derived bis(oxazoline) ligands are used that carry bulky benzyl substituents at the bridge and moderately bulky isopropyl groups on their core. The apparently homogeneous solution of CsF in C6F6/hexafluoroisopropanol (HFIP) is the best reaction medium, but CsF in the biphasic mixture CH2Cl2/HFIP also provides good results. DFT studies suggest that fluoride initially attacks the Cu- rather than the C-atom of the transient donor/acceptor carbene intermediate. This unusual step is followed by 1,2-fluoride shift; for this migratory insertion to occur, the carbene must rotate about the Cu?C bond to ensure orbital overlap. The directionality of this rotatory movement within the C2-symmetric binding site determines the sense of induction. This model is in excellent accord with the absolute configuration of the resulting product as determined by X-ray diffraction using single crystals of this a priori wax-like material grown by capillary crystallization.
Three-Component Synthesis of Isoquinoline Derivatives by a Relay Catalysis with a Single Rhodium(III) Catalyst
Zhou, Chao,Jiang, Jijun,Wang, Jun
supporting information, p. 4971 - 4975 (2019/09/03)
A rhodium(III)-catalyzed one-pot three-component reaction of N-methoxybenzamide, α-diazoester, and alkyne was developed, providing an alternative way to synthesize isoquinoline derivatives. Mechanistically, it is a relay catalysis, and the reaction occurred via successive O-alkylation and C-H activation processes, both of which were promoted by the same catalyst.
Photoinduced Palladium-Catalyzed Negishi Cross-Couplings Enabled by the Visible-Light Absorption of Palladium–Zinc Complexes
Abdiaj, Irini,Huck, Lena,Mateo, José Miguel,de la Hoz, Antonio,Gomez, M. Victoria,Díaz-Ortiz, Angel,Alcázar, Jesús
supporting information, p. 13231 - 13236 (2018/09/25)
A visible-light-induced Negishi cross-coupling is enabled by the activation of a Pd0–Zn complex. With this photocatalytic method, the scope of deactivated aryl halides that can be employed in the Negishi coupling was significantly expanded. NMR experiments conducted in the presence and absence of light confirmed that the formation of the palladium–zinc complex is key for accelerating the oxidative addition step.
Copper-catalyzed coupling of aryl iodides and tert-butyl keto esters: Efficient access to α-aryl ketones and α-arylacetic acid tert-butyl esters
Zhao, Duo,Jiang, Yongwen,Ma, Dawei
, p. 3327 - 3332 (2014/05/06)
CuI/trans-4-hydroxy-l-proline catalyzed coupling of aryl iodides with tert-butyl keto esters proceeded smoothly at 40 °C in DMF, providing α-aryl ketones after acid-promoted deprotection and decarboxylation of tert-butyl ester group. While CuI/2-picolinic acid catalyzed coupling of aryl iodides with tert-butyl acetoacetate at 70 °C in dioxane delivered α-arylacetic acid tert-butyl esters upon spontaneous deacylation. A wide range of functional groups, such as acetyl, methoxy, nitrile, nitro, bromo, and chloro were compatible with the reaction conditions.
Oxazaborolidinium ion-catalyzed cyclopropanation of α-substituted acroleins: Enantioselective synthesis of cyclopropanes bearing two chiral quaternary centers
Gao, Lizhu,Hwang, Geum-Sook,Ryu, Do Hyun
supporting information; experimental part, p. 20708 - 20711 (2012/02/06)
A catalytic synthetic route to highly functionalized chiral cyclopropane derivatives was developed by Michael-initiated cyclopropanation of α-substituted acroleins with aryl- and alkyl diazoacetates. In the presence of chiral (S)-oxazaborolidinium cation
Iron-catalyzed chemoselective cross-coupling of α-bromocarboxylic acid derivatives with aryl grignard reagents
Jin, Masayoshi,Nakamura, Masaharu
scheme or table, p. 1012 - 1014 (2011/12/05)
We have developed a simple and effective synthetic method of α-arylcarboxylic acid derivatives based on the iron-catalyzed cross-coupling reaction of α-bromocarboxylic acid derivatives with aryl Grignard reagents. The reaction proceeds smoothly at -78 °C in a chemoselective manner to produce the coupling product in good to excellent yields.
