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Cover Picture: Modulable and Highly Diastereoselective Carbometalations of Cyclopropenes (Chem. Eur. J. 4/2014) 下载免费PDF全文
Dr. Dorian Didier Dr. Pierre‐Olivier Delaye Marwan Simaan Biana Island Dr. Guillaume Eppe Dr. Hendrik Eijsberg Amir Kleiner Prof. Dr. Paul Knochel Prof. Dr. Ilan Marek 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(4):909-909
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Dr. Longyang Dian Dr. Daniel S. Müller Prof. Dr. Ilan Marek 《Angewandte Chemie (International ed. in English)》2017,56(24):6783-6787
The highly diastereo- and enantioselective formation of polysubstituted cyclopropanes was easily achieved through the asymmetric copper-catalyzed carbomagnesiation reaction of nonfunctionalized cyclopropene derivatives. The carbometalated species generated in situ readily undergo C−C and C−X bond-forming reactions with various electrophiles with complete retention of configuration. 相似文献
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Dr. Uyen P. N. Tran Renè Hommelsheim Zhen Yang Claire Empel Dr. Katharina J. Hock Dr. Thanh V. Nguyen Prof. Dr. René M. Koenigs 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(6):1254-1257
The synthesis of trifluoromethylated cyclopropenes is often associated with important applications in drug discovery and functional materials. In this report, we describe the use of readily available chiral rhodium(II) catalysts for a highly efficient asymmetric cyclopropenation reaction of fluorinated donor–acceptor diazoalkanes with a broad variety of aliphatic and aromatic alkynes. Further studies highlight the unique reactivity of fluorinated donor–acceptor diazoalkanes in the synthesis of oligo-cyclopropenes. Subsequent C−H functionalization of trifluoromethyl cyclopropenes furnishes densely substituted cyclopropene frameworks and also allows the alternative synthesis of bis-cyclopropenes. 相似文献
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Liangliang Zhang Prof. Dr. Martin Oestreich 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(63):14304-14307
A highly stereocontrolled syn-addition of silicon nucleophiles across cyclopropenes with two different geminal substituents at C3 is reported. Diastereomeric ratios are excellent throughout (d.r.≥98:2) and enantiomeric excesses usually higher than 90 %, even reaching 99 %. This copper-catalyzed C−Si bond formation closes the gap of the direct synthesis of α-chiral cyclopropylsilanes. 相似文献
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Differently substituted 2‐alkoxyfurans (2,3,4‐ or 2,3,5‐trisubstituted furans) were highly regioselectively synthesized by means of the ring‐opening cycloisomerization of the same cyclopropenyl carboxylates with good yields in different solvents and excellent regioselectivity by using [Cu(acac)2] (acac=acetylacetonate) or [RuCl2(PPh3)3] as the catalyst, respectively. The structures of these two different types of furans were established by X‐ray diffraction studies. A rationale has been proposed. 相似文献
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Rhodium‐Catalyzed Arylation of Cyclopropenes Based on Asymmetric Direct Functionalization of Three‐Membered Carbocycles 下载免费PDF全文
Dr. Longyang Dian Prof. Dr. Ilan Marek 《Angewandte Chemie (International ed. in English)》2018,57(14):3682-3686
A variety of highly diastereo‐ and enantiomerically enriched arylcyclopropanes is obtained through the asymmetric rhodium‐catalyzed arylation reaction of achiral nonfunctionalized cyclopropene derivatives with commercially available aryl boronic acids in the presence of (R,S)‐Josiphos. 相似文献
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Morgan Cormier Aurélien de la Torre Ilan Marek 《Angewandte Chemie (International ed. in English)》2018,57(40):13237-13241
Trialkylaluminum compounds perform a diastereoselective 1,6‐ring fragmentation of alkenylcyclopropane. This new tool allows the preparation of hydrocarbon compounds containing two distant stereocenters with a good diastereocontrol. Inspired by the biosynthesis of botryococcene this methodology was applied successfully to the diastereo‐ and enantioselective preparation of this triterpene and its epimer. 相似文献
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Michael G. Yang Dilip P. Modi Ruth R. Wexler Richard E. Olson 《Tetrahedron letters》2004,45(1):111-112
A new procedure for the diastereoselective alkylations of β-tetrazolyl propionic acids is described. A seven-membered chelation model is proposed to rationalize the observed high level of syn selectivity. 相似文献
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Efficient Synthesis of Arylated Furans by a Sequential Rh‐Catalyzed Arylation and Cycloisomerization of Cyclopropenes 下载免费PDF全文
Dr. Xiaoming Wang Andreas Lerchen Dr. Constantin G. Daniliuc Prof. Frank Glorius 《Angewandte Chemie (International ed. in English)》2018,57(6):1712-1716
A novel and efficient strategy for the synthesis of arylated furans was successfully developed by a RhIII‐catalyzed coupling of N‐phenoxyacetamides and cyclopropenyl esters. Mechanistic investigation reveals that the arylated furans are formed via arylation of the cyclopropenyl esters followed by cycloisomerization. 相似文献
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Taming the Carboxyl Group for Directed Carbometalation: Observations on the Use of Anions,Dianions and Ester Enolates 下载免费PDF全文
Dr. Sandy Desrat Dr. Philip J. Gray Dr. Matthew R. Penny Prof. Dr. William B. Motherwell 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(29):8918-8922
Carboxylate anions, dianions and ester enolates provide simultaneous protection and activation for directed carbometalation reactions. Advantage can be taken of the bis‐carbanionic character of the intermediate for further controlled C?C bond forming reactions. 相似文献
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Highly Diastereoselective and Regioselective Copper‐Catalyzed Nitrosoformate Dearomatization Reaction under Aerobic‐Oxidation Conditions 下载免费PDF全文
Weibo Yang Long Huang Yang Yu Daniel Pflästerer Dr. Frank Rominger Prof. Dr. A. Stephen K. Hashmi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(14):3927-3931
An unprecedented copper‐catalyzed acylnitroso dearomatization reaction, which expands the traditional acylnitroso ene reaction and acylnitroso Diels–Alder reaction to a new type of transformation, has been developed under aerobic oxidation. Intermolecular and intra‐/intermolecular reaction modes demonstrate an entirely different N‐ or O‐acylnitroso selectivity. Hence, we can utilize this reaction as a highly diastereoselective access to a series of new pyrroloindoline derivatives, which are important structural motifs for natural‐product synthesis. 相似文献
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Hashmi AS Rivas Nass A Bats JW Bolte M 《Angewandte Chemie (International ed. in English)》1999,38(22):3370-3373
Unexpected stability is observed for the palladacycloheptane rac-2, which is obtained as major product and single diastereomer from the cyclization of 1 and Pd(0). Up to a temperature of 50 degrees C 2 shows neither reductive elimination nor intramolecular insertion of another olefin. 相似文献
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An anti-selective reductive aldol reaction of a Boc-protected, 2-substituted pyrrole is reported. Reduction with LiDBB generates an exocyclic lithium enolate, but optimal stereoselectivity is obtained by transmetallation to magnesium with MgBr2·OEt2. The corresponding syn-aldols can easily be obtained (protected as carbamates) by subsequent inversion. 相似文献
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Yasutaka Yatsumonji Takuya Nishimura Akira Tsubouchi Dr. Keiichi Noguchi Prof. Takeshi Takeda Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(11):2680-2686
A route with less congestion : A practical method for the highly diastereoselective preparation of anti tertiary homoallylic alcohols has been developed. The reaction of allyltitanocenes, generated by the reductive titanation of various allylic substrates with a titanocene(II) species, with a variety of ketones produced the anti tertiary homoallylic alcohols in good diastereoselectivity, even when using sterically less congested ketones (see scheme; Cp: cyclopentadienyl; Piv: pivaloyl).
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Anna N. Philippova Daria V. Vorobyeva Pavel S. Gribanov Fedor M. Dolgushin Sergey N. Osipov 《Molecules (Basel, Switzerland)》2022,27(20)
An efficient way to access highly functionalized proline derivatives was developed based on a Cu(I)-catalyzed reaction between CF3-substituted allenynes and tosylazide, which involved a cascade of [3 + 2]-cycloaddition/ketenimine and a rearrangement/Alder-ene cyclization to afford the new proline framework with a high diastereoselectivity. 相似文献
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Jassem A. M. Raheemah A. H. Radhi W. A. Alid A. M. Jaber H. A. 《Russian Journal of Organic Chemistry》2019,55(10):1598-1603
Russian Journal of Organic Chemistry - A four-step procedure has been developed for the synthesis of (S)-3-isopropyl-1-[(R)-1-phenylethyl)- 1,4-diazaspiro[4.5]decan-2-one with high... 相似文献