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1.
Shuanglin Qin Yunhao Luo Yue Sun Le Tian Shende Jiang Jun yan Guang Yang 《Tetrahedron letters》2019,60(43):151167
In the present study, an inexpensive but efficient Iron(III) and Copper(II) co-catalyst without ligands catalyzed arylation of sulfinamides with aryl iodide was primarily reported. In brief, in the presence of Fe(NO3)3·9H2O, CuO and K3PO4, the highly selective C–N cross coupling of several sulfinamides and aryl iodides was achieved in high chemical yield, while the aryl chlorides and bromides could not yield coupling products. It is noteworthy that through the arylation of chiral tert-butanesulfinamide with aryl iodides, N-aryl tert-butanesulfinamides are provided without racemization, even in gram-scale. The possible mechanism was that This oxidative addition process between copper catalyst and aryl-iodides might be significantly accelerated by active Fe(III) species. Moreover, using this synthetic method, a facile and efficient access was developed for the derivatives of N-phenyl sulfinamides, which might help to develop new drug molecules and material chemicals. 相似文献
2.
Chen Li Kun Zhang Hongrui Ma Shuang Wu Yilei Huang Yafei Duan Yunhao Luo Prof. Jun Yan Prof. Guang Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(70):e202202190
C−N bond formation takes on a critical significance in reactions of organic synthesis, material production and pharmaceutical manufactory. Chan-Lam has proposed a useful methodology to furnish secondary arylamides under mild conditions. However, when chiral sulfinamides serve as the coupling precursors, the Cu-catalyzed coupling reaction is found with low efficacy. Complex side-products are generated under classic conditions. Moreover, it led to the racemization of the coupling product. In this study, an optimized Ni-catalyzed Chan-Lam type coupling conditions were proposed, which resulted in clean conversion from chiral sulfinamides and arylboronic acids to offer N-aryl sulfinamides efficiently and enantioretentively. The trans-N1,N2-dimethylcyclohexane-1,2-diamine was proven as the most efficient ligand. Under the optimized conditions, a series of chiral N-aryl sulfinamides was prepared with high chemical yield without racemization. Furthermore, a plausible and novel mechanism was proposed. Interestingly, the method could efficiently furnish a wide variety of C−X bonds by coupling arylboronic acids with different nucleophiles. 相似文献
3.
A general method to obtain enantioenriched 1,3,3-triarylpropan-1-ones bearing a diarylmethine stereocenter was developed using Rh/chiral sulfinylphosphine catalyzed 1,4-addition of arylboronic acids to chalcones. The catalysis progressed smoothly in the presence of 2 mol % catalyst formed in situ from [Rh(C2H4)2Cl]2 and chiral tert-butanesulfinylphosphine and gave the adducts with up to 99% yield and 98% ee. 相似文献
4.
Eui Ta Choi 《Tetrahedron》2008,64(7):1515-1522
Catalytic asymmetric dehydration of β-aryl or alkyl substituted β-hydroxy esters via kinetic resolution has been investigated. A brief survey of 10 different chiral ligands is conducted to examine the effects of chiral ligand structure on selectivity of the dehydration. The kinetic resolution of a variety of rac-β-hydroxy tert-butyl esters in the presence of prolinol chiral ligand 2 and BrZnCH2CO2-t-Bu can provide highly enantioenriched β-hydroxy esters 14-21 with selectivity factors ranging from 11 to 66. Also, application of this asymmetric synthetic methodology to the preparation of enantioenriched flavane derivatives 25-29 is demonstrated. 相似文献
5.
Xuemeng Chen Prof. Dr. Zhong Lian Prof. Dr. Søren Kramer 《Angewandte Chemie (International ed. in English)》2023,62(13):e202217638
A method for direct access to enantioenriched benzylic amides and carbamate-protected primary benzylamines by C−H functionalization is reported. The C−H substrate is used as limiting reagent with only a small excess of the unactivated amide or carbamate nucleophile. The enantioselective intermolecular dehydrogenative C−N bond formation is enabled by a combination of a chiral copper catalyst, a photocatalyst, and an oxidant, and it takes place under mild conditions, which allow for a broad substrate scope. The method is compatible with late-stage C−H functionalization, and it provides easy access to 15N-labeled amides and amines starting from cheap 15NH4Cl. 相似文献
6.
Synthesis of Secondary and Tertiary Alkyl Boronic Esters by gem‐Carboborylation: Carbonyl Compounds as Bis(electrophile) Equivalents
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Dunfa Shi Dr. Lu Wang Prof. Dr. Chungu Xia Prof. Dr. Chao Liu 《Angewandte Chemie (International ed. in English)》2018,57(32):10318-10322
An unprecedent gem‐carboborylation of aldehydes and ketones provides access to various secondary and tertiary alkyl boronic esters. The addition of B2pin2 to a carbonyl compound generates α‐oxyl‐substituted alkyl boron species. Organolithium and Grignard reagents are then applied as C nucleophiles for the 1,2‐metalate rearrangement process. The organolithium reagents can also be generated by C?H lithiation or halogen/lithium exchange. The use of chiral ligands led to the generation of chiral alkyl boronic esters in enantioenriched form, demonstrating that the enantioselectivity of this transformation is catalyst‐controlled. 相似文献
7.
Andrea Cataffo Dr. Miguel Peña-López Riccardo Pedrazzani Antonio M. Echavarren 《Angewandte Chemie (International ed. in English)》2023,62(49):e202312874
Two different classes of stereoselective cyclizations have been developed using a chiral auxiliary approach with commercially available [JohnPhosAu(MeCN)SbF6] as catalyst. First, a stereoselective cascade cyclization of 1,5-enynes was achieved using the Oppolzer camphorsultam as chiral auxiliary. In this case, a one-pot cyclization-hydrolysis sequence was developed to directly afford enantioenriched spirocyclic ketones. Then, the stereoselective alkoxycyclization of 1,6-enynes was mediated by an Evans-type oxazolidinone. A reduction-hydrolysis sequence was selected to remove the auxiliary to give enantioenriched β-tetralones. DFT studies confirmed that the steric clash between the chiral auxiliary and alkene accounts for the experimentally observed diastereoselective cyclization through the Si face. 相似文献
8.
Dong‐Yang Zhang Ying Zhang Hua Wu Liu‐Zhu Gong 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(22):7528-7531
An enantioselective catalytic alkoxylation/oxidative rearrangement of allylic alcohols has been established by using a Brønsted acid and chiral organoiodine. The presence of 20 mol % of an (S)‐proline‐derived C2‐symmetric chiral iodine led to enantioenriched α‐arylated β‐alkoxylated ketones in good yields and with high levels of enantioselectivity (84–94 % ee). 相似文献
9.
Dr. Zhenli Luo Dr. Zhewei Li Dr. Haoqiang Zhao Dr. Ji Yang Prof. Lijin Xu Prof. Ming Lei Prof. Qinghua Fan Prof. Patrick J. Walsh 《Angewandte Chemie (International ed. in English)》2023,62(32):e202305449
Recent years have witnessed marked progress in the efficient synthesis of various enantioenriched 1,2,3,4-tetrahydroquinoxalines. However, enantio- and diastereoselective access to trans-2,3-disubstituted 1,2,3,4-tetrahydroquinoxalines remains much less explored. Herein we report that a frustrated Lewis pair-based catalyst generated via in situ hydroboration of 2-vinylnaphthalene with HB(C6F5)2 allows for the one-pot tandem cyclization/hydrosilylation of 1,2-diaminobenzenes and 1,2-diketones with commercially available PhSiH3 to exclusively afford trans-2,3-disubstituted 1,2,3,4-tetrahydroquinoxalines in high yields with excellent diastereoselectivities (>20 : 1 dr). Furthermore, this reaction can be rendered asymmetric by using an enantioenriched borane-based catalyst derived from HB(C6F5)2 and a binaphthyl-based chiral diene to give rise to enantioenriched trans-2,3-disubstituted 1,2,3,4-tetrahydroquinoxalines in high yields with almost complete diastereo- and enantiocontrol (>20 : 1 dr, up to >99 % ee). A wide substrate scope, good tolerance of diverse functionality and up to 20-gram scale production are demonstrated. The enantio- and diastereocontrol are achieved by the judicious choice of borane catalyst and hydrosilane. The catalytic pathway and the origin of the excellent stereoselectivity are elucidated by mechanistic experiments and DFT calculations. 相似文献
10.
P. K. Claus H. A. Schwarz W. Rieder W. Vycudilik 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):11-18
Abstract N-Aryl-S,S-dialkylsulfimides, 1, with R1 = alkyl other than CH3, have been rearranged by heating in ethanol yielding o-alkylthiomethyl-anilines, 2, as main products. Isomeric o-methylthioalkyl-anilines, 14, are formed in minor amounts only. Reactions of sulfimides, 1, with R1 = CH3, with certain alkylating or acylating agents yielded o-methylthiomethylated, N-alkylated or -acylated products 9. Mechanistic considerations are discussed. The rearrangement of sulfimides 1 has been assumed to occur via [2,3]-sigmatropic reactions of intermediate azasulfonium ylids 3. Attempts to resolve (+)-camphor-10-sulfonates of N-aryl sulfimides failed, but optically active N-aryl sulfimides could be obtained by reaction of anilines with optically active sulfoxides and P4O10. Optically active 2,6-disubstituted sulfimides, 1, could be rearranged in ethanolic KOH to yield optically active cyclohexadienimines 12, indicating a transfer of asymmetry from sulfur to carbon and supporting the assumption of a sigmatropic rearrangement. 相似文献
11.
A simple, general, and practical technology to prepare enantiopure 1,2,3-oxathiazolidine-2-oxide derivatives using chiral aryl N-sulfonyl aminoalcohol derivatives and thionyl chloride is reported. The versatility of these novel chiral building blocks (MIOO and TMPOO), was exemplified by the expedient production of a variety of unique chiral sulfoxides and valuable chiral sulfinamides in excellent yields and enantiopurities. 相似文献
12.
Xiaobo He Jingchao Chen Xin Xu Fan Yang Cuiping Gu Yongyun Zhou Baomin Fan 《Tetrahedron: Asymmetry》2017,28(1):62-68
The asymmetric ring opening reactions of oxabenzonorbornadienes with carboxylic acids are described. By using the complex of [Rh(COD)Cl]2 and (S,S)-BDPP, with ZnI2 as the co-catalyst, a range of aromatic acids and alkyl acids were utilized as nucleophiles to afford the corresponding chiral hydronaphthalene products with high enantioselectivities (84–94% ee). Thus, the present methodology has provides an effective synthetic method for the preparation of enantioenriched hydronaphthalenes. 相似文献
13.
《Tetrahedron》2019,75(23):3063-3079
The -CHF2 moiety has shown a growing interest in pharmaceutical and agrochemical applications over the last few years. Its introduction is therefore a current research topic for organic chemists. Several groups have reported the synthesis of difluoromethylated compounds. However, the more challenging enantioselective introduction of the difluoromethyl group has been scarcely described yet. We recently developed a new strategy, based on the use of an enantiopure difluoromethyl sulfoxide used as chiral and traceless auxiliary, for the synthesis of highly enantioenriched α-difluoromethyl alcohols. The first method developed in our laboratory aims to access highly stereoenriched α,α-difluoro-β-hydroxysulfoxides through the condensation of the enantiopure difluoromethyl sulfoxide on carbonyl derivatives. It is noteworthy that highly diastereo- and enantioenriched α,α-difluoro-β-hydroxysulfoxides can also be accessed after the diastereoselective reduction of highly enantioenriched α,α-difluoro-β-ketosulfoxides. Finally, the expected difluoromethyl-substituted alcohols can be obtained after removal of the chiral auxiliary with complete retention of stereoenrichment at carbon. 相似文献
14.
Carboalumination of alkynes in the presence of catalytic Cp2ZrCl2 and H2O affords vinyl‐alane intermediates, which serve as nucleophiles in the subsequent addition to enantiomerically enriched (tert‐butyl)‐ and (para‐tolyl)sulfinimines. This new in situ protocol produces two new C C bonds. Chiral allylic sulfinamides are obtained in high diastereoselectivity and in good yield. Cleavage of the chiral auxiliary leads to synthetically useful allylic amine building blocks, and facile oxidative degradation of the alkene moiety can be used as an approach toward amino acid derivatives and for assignment of absolute configuration. 相似文献
15.
Combining Organocatalysis with Central‐to‐Axial Chirality Conversion: Atroposelective Hantzsch‐Type Synthesis of 4‐Arylpyridines
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Ophélie Quinonero Marion Jean Dr. Nicolas Vanthuyne Prof. Dr. Christian Roussel Dr. Damien Bonne Prof. Dr. Thierry Constantieux Prof.Dr. Cyril Bressy Dr. Xavier Bugaut Prof. Dr. Jean Rodriguez 《Angewandte Chemie (International ed. in English)》2016,55(4):1401-1405
Suitably substituted enantioenriched 4‐aryl‐1,4‐dihydro‐pyridines prepared by an organocatalytic enantioselective Michael addition were oxidized with MnO2 into axially chiral 4‐arylpyridines with central‐to‐axial chirality conversion. Moderate to complete percentages (cp) were observed, and a model for the conversion of chirality is discussed. 相似文献
16.
Enantioselective Copper‐Catalyzed Decarboxylative Propargylic Alkylation of Propargyl β‐Ketoesters with a Chiral Ketimine P,N,N‐Ligand
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Fu‐Lin Zhu Yuan Zou De‐Yang Zhang Ya‐Hui Wang Xin‐Hu Hu Song Chen Prof. Dr. Jie Xu Prof. Dr. Xiang‐Ping Hu 《Angewandte Chemie (International ed. in English)》2014,53(5):1410-1414
The first enantioselective copper‐catalyzed decarboxylative propargylic alkylation has been developed. Treatment of propargyl β‐ketoesters with a catalyst, prepared in situ from [Cu(CH3CN)4BF4] and a newly developed chiral tridentate ketimine P,N,N‐ligand under mild reaction conditions, generates β‐ethynyl ketones in good yields and with high enantioselectivities without requiring the pregeneration of ketone enolates. This new process provides facile access to a range of chiral β‐ethynyl ketones in a highly enantioenriched form. 相似文献
17.
Jianguang Liu Yingying Tian Jialing Shi Shasha Zhang Qian Cai 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(37):11067-11070
Spirobicyclic structures are versatile building blocks for functional chiral molecules. An enantioselective synthesis of chiral spirobilactams via a copper‐catalyzed double N‐arylation was developed. Amplification of solution ee by in situ precipitation of the racemate was observed with this method and enantioenriched spirobilactams were obtained with excellent ee values through simple solid–solution phase separation. 相似文献
18.
A convenient and practical method for the preparation of enantiomerically pure α-trifluoromethylated α-propargylamines is described. A range of enantiopure α-trifluoromethylated α-propargyl sulfinamides were obtained by the addition of lithium acetylides generated in situ with n-BuLi and terminal alkynes to diverse chiral CF3-substituted (S)-N-tert-butanesulfinyl ketimines in moderate to excellent yields (56–97%) and with uniformly excellent diastereoselectivities (>99:1) by using Ti(OiPr)4 as the catalyst and THF as the polar solvent. Enantiomerically pure α-trifluoromethylated α,α-dibranched propargyl amines were then readily obtained in excellent yields (87–97%) by acidic cleavage of the tert-butanesulfinyl group. 相似文献
19.
de Ceglie MC Musio B Affortunato F Moliterni A Altomare A Florio S Luisi R 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(1):286-296
A highly stereo‐ and regioselective functionalisation of chiral non‐racemic aziridines is reported. By starting from a parent enantioenriched aziridine and finely tuning the reaction conditions, it is possible to address the regio‐ and stereoselectivity of the lithiation/electrophile trapping sequence, thereby allowing the preparation of highly enantioenriched functionalised aziridines. From chiral N‐alkyl trans‐2,3‐diphenylaziridines (S,S)‐ 1 a , b , two differently configured chiral aziridinyllithiums could be generated (trans‐ 1 a , b‐Li in toluene and cis‐ 1 a , b‐Li in THF), thus disclosing a solvent‐dependent reactivity that is useful for the synthesis of chiral tri‐substituted aziridines with different stereochemistry. In contrast, chiral aziridine (S,S)‐ 1 c showed a temperature‐dependent reactivity to give chiral ortho‐lithiated aziridine 1 c‐ ortho ‐Li at ?78 °C and α‐lithiated aziridine 1 c‐α‐Li at 0 °C. Both lithiated intermediates react with electrophiles to give enantioenriched ortho‐ and α‐functionalised aziridines. The reaction of all the lithiated aziridines with carbonyl compounds furnished useful chiral hydroxyalkylated derivatives, the stereochemistry of which was ascertained by X‐ray and NMR spectroscopic analysis. The usefulness of chiral non‐racemic functionalised aziridines has been demonstrated by reductive ring‐opening reactions furnishing chiral amines that bear quaternary stereogenic centres and chiral 1,2‐, 1,3‐ and 1,5‐aminoalcohols. It is remarkable that the solvent‐dependent reactivity observed with (S,S)‐ 1 a , b permits the preparation of both the enantiomers of amines ( 11 and ent‐ 11 ) and 1,2‐aminoalcohols ( 13 and ent‐ 13 ) starting from the same parent aziridine. Interestingly, for the first time, a configurationally stable chiral α‐lithiated aziridine ( 1 c‐α‐Li ) has been generated at 0 °C. In addition, ortho‐hydroxyalkylated aziridines have been easily converted into chiral aminoalkyl phthalans, which are useful building blocks in medicinal chemistry. 相似文献
20.
Stereospecific Pd‐Catalyzed Intermolecular C(sp3)–C(sp) Cross‐Coupling of Diarylmethyl Carbonates and Terminal Alkynes Under Base‐Free Conditions
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Sho Tabuchi Prof. Dr. Koji Hirano Prof. Dr. Masahiro Miura 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):16823-16827
A palladium‐catalyzed intermolecular decarboxylative C(sp3)–C(sp) coupling of diarylmethyl carbonates and terminal alkynes has been developed. The reaction proceeds smoothly under external base‐free conditions to deliver the corresponding alkynylated diarylmethanes with the liberation of CO2 and MeOH as the sole byproducts. Moreover, enantioenriched diarylmethyl carbonates are stereospecifically converted to optically active cross‐coupling products with inversion of configuration. Thus, the stereospecific palladium catalysis can provide new and unique access to the alkynylated chiral tertiary stereocenters, which are relatively difficult to construct by conventional methods. 相似文献