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Search for "asymmetric catalysis" in Full Text gives 141 result(s) in Beilstein Journal of Organic Chemistry.
Asymmetric Michael addition reactions catalyzed by calix[4]thiourea cyclohexanediamine derivatives
Beilstein J. Org. Chem. 2018, 14, 1901–1907, doi:10.3762/bjoc.14.164
- reactions in aqueous solution with excellent enantioselectivity [35]. As part of our ongoing studies to develop novel types of organocatalysts for asymmetric catalysis, in this study, we aimed to synthesize novel upper rim-functionalized calix[4]thiourea cyclohexanediamine derivatives to catalyze asymmetric
Recent advances in hypervalent iodine(III)-catalyzed functionalization of alkenes
Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154
- hypervalent iodine(III)-catalyzed functionalization of alkenes and asymmetric reactions using a chiral iodoarene are summarized. Keywords: asymmetric catalysis; functionalization of alkenes; hypervalent iodine(III); Introduction Hypervalent iodine(III) reagents, also named as λ3-iodanes, have been widely
Enantioselective phase-transfer catalyzed alkylation of 1-methyl-7-methoxy-2-tetralone: an effective route to dezocine
Beilstein J. Org. Chem. 2018, 14, 1421–1427, doi:10.3762/bjoc.14.119
- -dibromopentane, and the best catalyst (C7) was identified. In addition, optimizations of the alkylation were carried out so that the process became practical and effective. Keywords: alkylation; asymmetric catalysis; cinchonidine; dezocine; Introduction The preparation of enantiomerically pure compounds has
- become a stringent requirement for pharmaceutical synthesis [1]. In this context, asymmetric catalysis is probably one of the most attractive procedures for the synthesis of active pharmaceutical ingredients (APIs) due to environmental, operational, and economic benefits. Dezocine, (5R,11S,13S)-13-amino
- separated by two times of resolution with L-tartaric acid and D-tartaric acid (Scheme 1). Phase-transfer asymmetric catalysis with cinchona alkaloid-derived quaternary ammonium compounds has become one of the topics in stereoselective synthesis in both industry and academia [6][7][8][9]. It was reported [10
Recent applications of chiral calixarenes in asymmetric catalysis
Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117
- Analysis Technological Application and Research Center (UBATAM), Usak University, Usak, Turkey Vocational School of Health Services, Usak University, 64200 Usak, Turkey 10.3762/bjoc.14.117 Abstract The use of calixarenes in asymmetric catalysis is receiving increasing attention due to their tunable three
- -dimensional molecular platforms along with their easy syntheses and versatile modification at the upper and lower rims. This review summarizes the recent progress of synthesis and use of chiral calixarenes in asymmetric syntheses which emerged later than 2010. Keywords: asymmetric catalysis; chiral
- asymmetric catalysis has received considerable interest and witnessed significant progress in recent years [2][3][4]. Calixarenes are considered as the third generation of supramolecular hosts after cyclodextrins and crown ethers [5][6]. Due to their easy preparation and readily modification at either the
A survey of chiral hypervalent iodine reagents in asymmetric synthesis
Beilstein J. Org. Chem. 2018, 14, 1244–1262, doi:10.3762/bjoc.14.107
- of an external oxidant. The use of catalytic chiral hypervalent iodine reagents in asymmetric catalysis is one of the most challenging ongoing topics and this review will focus on the development of various chiral hypervalent iodine reagents and their application in typical organic transformations
An overview of recent advances in duplex DNA recognition by small molecules
Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93
- -based asymmetric catalysis by synthesizing various structural analogs of Hoechst 33258. It has been observed that amine analogs (conjugate 53 and 54) showed higher affinity towards ct-DNA and poly[d(A·T)2] in comparison to alkyne analogs with reduced flexibility and one less charged nitrogen atom
Nanoreactors for green catalysis
Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61
- and, thereby, harness its utility for further applications. The abovementioned issues are particularly relevant in the field of asymmetric catalysis, which besides overcoming catalyst compatibility also has to deal with cost issues [11][12]. Research on asymmetric catalysis has been mainly focused on
Investigations towards the stereoselective organocatalyzed Michael addition of dimethyl malonate to a racemic nitroalkene: possible route to the 4-methylpregabalin core structure
Beilstein J. Org. Chem. 2018, 14, 553–559, doi:10.3762/bjoc.14.42
- based on chiral phase-transfer-catalysis of the Michael addition was also reported [26]. In this context, we decided to develop a synthesis of 4-methylpregabalin from a simple and achiral starting material and build its chirality centers using asymmetric catalysis. This paper describes the synthesis of
Recent developments in the asymmetric Reformatsky-type reaction
Beilstein J. Org. Chem. 2018, 14, 325–344, doi:10.3762/bjoc.14.21
- benzoxathiazine 2,2-dioxides, as electrophiles in the catalytic enantioselective aza-Reformatky reaction [49]. Indeed, these compounds constitute good partners for asymmetric catalysis since they exhibit a rigid structure reducing the conformational mobility and avoiding the E/Z isomerization, thus facilitating
Photocatalytic formation of carbon–sulfur bonds
Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4
- substances used in material synthesis bear sulfur-containing functional groups. Furthermore, the unique chemical properties of sulfur find applications in asymmetric catalysis or material design [14][15][16][17][18][19]. Therefore, many well established and highly efficient strategies for the formation of C
Exploring mechanochemistry to turn organic bio-relevant molecules into metal-organic frameworks: a short review
Beilstein J. Org. Chem. 2017, 13, 2416–2427, doi:10.3762/bjoc.13.239
- and materials sciences, including organic solids [2] with pharmaceutical, luminescence- and thermoactive properties; studies of biomolecular recognition, asymmetric catalysis, interlocked systems and racemic resolution [2]. More recently mechanochemical methods were again successfully applied to the
Conjugated nitrosoalkenes as Michael acceptors in carbon–carbon bond forming reactions: a review and perspective
Beilstein J. Org. Chem. 2017, 13, 2214–2234, doi:10.3762/bjoc.13.220
- nucleophile as well as asymmetric catalysis still remains to be studied in these reactions. The high efficiency and stereoselectivity of the enolate addition to nitrosoalkenes make this strategy perspective for application in total synthesis that has been recognized since 1970s. Thus, Oppolzer and co-workers
Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles
Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170
- Johannes Schorgenhumer Maximilian Tiffner Mario Waser Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria 10.3762/bjoc.13.170 Abstract Chiral phase-transfer catalysis is one of the major catalytic principles in asymmetric catalysis. A broad
- a variety of highly versatile methods for asymmetric catalysis [24][55][56][57][58][59][60][61][62][63]. In contrast to chiral cation-based PTCs, which mainly operate through coordination and control of the nucleophile, these anionic PTCs usually coordinate cationic (and often hardly soluble
- -chlorination of β-ketoesters 1, by using N-chlorosuccinimide (14) as the Cl-transfer agent [76]. In continuation of our efforts to develop bifunctional ammonium salts D for asymmetric catalysis we have also recently investigated the asymmetric synthesis of α-chloroketoesters 12 [92]. We found that catalyst
Construction of highly enantioenriched spirocyclopentaneoxindoles containing four consecutive stereocenters via thiourea-catalyzed asymmetric Michael–Henry cascade reactions
Beilstein J. Org. Chem. 2017, 13, 1342–1349, doi:10.3762/bjoc.13.131
- spirocyclopentaneoxindoles containing multiple contiguous stereocenters remains challenging [23][24][25][26]. The medicinal properties of these frameworks mean that fast enrichment of spirooxindoles bearing diverse functional groups is of considerable importance. Recently, an increasing number of asymmetric catalysis
Strategies in asymmetric catalysis
Beilstein J. Org. Chem. 2017, 13, 63–64, doi:10.3762/bjoc.13.8
- Tehshik P. Yoon Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, WI 53706, USA 10.3762/bjoc.13.8 Keywords: asymmetric catalysis; enantioselectivity; stereoselectivity; The stereochemistry of an organic compound can have a profound influence on many of
- reactions. Those of us with research interests in stereoselective synthesis lauded this award because it celebrated the creative insights of these pioneers in asymmetric catalysis and because it marked a general recognition that enantioselective catalysis has had a significant practical impact on the
- of asymmetric catalytic systems remains an active and vital research area. Current progress in the field of asymmetric catalysis continues to be driven both by conceptual innovations as well as demonstrations of the applicability of enantioselective catalytic reactions to increasingly complex
New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation
Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283
- and are critical for the resolution. This example clearly demonstrate the great potential of halogen bonds as tools for asymmetric catalysis. Early uses of halogen bond donors in catalysis and organocatalysis Like hydrogen bonds, halogen bonds possess important features such as strength and
Chromium(II)-catalyzed enantioselective arylation of ketones
Beilstein J. Org. Chem. 2016, 12, 2771–2775, doi:10.3762/bjoc.12.275
- ; asymmetric catalysis; chromium; ketone; tertiary alcohol; Introduction Catalytic enantioselective carbon–carbon bond formation reactions have achieved enormous development during the last few decades as a consequence of the growing demand for enantiopure compounds in modern industry, especially the
Green chemistry
Beilstein J. Org. Chem. 2016, 12, 2763–2765, doi:10.3762/bjoc.12.273
- , including “Strategies in asymmetric catalysis” by Tehshik P. Yoon [6], “Organometallic chemistry” by Bernd F. Straub and Lutz H. Gade [7], “C–H functionalization/activation in organic synthesis” by Richmond Sarpong [8], “Bifunctional catalysis” by Darren J. Dixon [9], “Sustainable catalysis” by Nicholas J
Experimental and theoretical investigations into the stability of cyclic aminals
Beilstein J. Org. Chem. 2016, 12, 2280–2292, doi:10.3762/bjoc.12.221
- Tetraponera sp. [1][2]. It is also present in ligands of ruthenium-based catalysts for metathesis [3], in imidazolidines acting as antiprotozoal and antibacterial agents [4][5], in Tröger’s base derivatives with diverse applications [6][7][8][9][10][11][12][13][14] (e.g., asymmetric catalysis, supramolecular
Chiral ammonium betaine-catalyzed asymmetric Mannich-type reaction of oxindoles
Beilstein J. Org. Chem. 2016, 12, 2099–2103, doi:10.3762/bjoc.12.199
- quaternary and tertiary stereogenic carbon centers on biologically intriguing molecular frameworks with high fidelity. Keywords: ammonium betaine; asymmetric catalysis; Mannich reaction; organocatalysis; oxindole; Introduction Chiral indole alkaloids possessing C-3 quaternary indoline frameworks are an
Enantioconvergent catalysis
Beilstein J. Org. Chem. 2016, 12, 2038–2045, doi:10.3762/bjoc.12.192
- %. Three mechanistically distinct approaches to effecting enantioconvergent catalysis are identified, and recent examples of each are highlighted. These processes are compared to related, non-enantioconvergent methods. Keywords: asymmetric catalysis; enantioselectivity; synthetic methods; Review
- product in high chemical yield (Figure 1b). Noyori has stated that this complex transformation is an “ideal asymmetric catalysis” [6]. There are several potential challenges in designing such a reaction, including kinetic resolution of the starting material and double stereodifferentiation [7] of
- success. Continuing development in this field may lead to the “ideal asymmetric catalysis” [3]. Enantioconvergent methods. Stereomutative enantioconvergent catalysis. Stereoablative enantioconvergent catalysis. Enantioconvergent parallel kinetic resolution. Dynamic kinetic resolution by hydrogenation
Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes
Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184
- regioselectivity can be enhanced by the use of asymmetric catalysis or chiral substrates. In addition, there are reported alterations to the diene, dienophile, or reaction conditions that are able to improve the regioselectivity for a given reaction. In a solution-phase nitroso hetero-Diels–Alder reaction between
- results from various electronic effects and the stereoselectivity can be influenced by the use of chiral dienes or dienophiles or the application of asymmetric catalysis. These methods, mainly the last one, take place in solution, while the solid-phase approaches described in the literature were not
From supramolecular chemistry to the nucleosome: studies in biomolecular recognition
Beilstein J. Org. Chem. 2016, 12, 1863–1869, doi:10.3762/bjoc.12.175
- organometallic methodology, asymmetric catalysis, total synthesis, and mechanistic studies. I opted for the latter and spent my Ph.D. studying the mechanism of the Wulff–Dötz reaction [1], while at the same time gaining a broad background in methodology and synthesis (Figure 2). I had a fantastic time in
Enantioselective addition of diphenyl phosphonate to ketimines derived from isatins catalyzed by binaphthyl-modified organocatalysts
Beilstein J. Org. Chem. 2016, 12, 1551–1556, doi:10.3762/bjoc.12.149
- reaction time, and low temperature required for good enantioselectivity. Thus, new approaches for the organocatalytic enantioselective addition of diphenyl phosphonate to isatin imines are highly desired. In connection with our ongoing research program on the design and application in asymmetric catalysis
Synthesis of 2-substituted tetraphenylenes via transition-metal-catalyzed derivatization of tetraphenylene
Beilstein J. Org. Chem. 2016, 12, 1302–1308, doi:10.3762/bjoc.12.122
- nonplanar distinct saddle-shaped structure [3][4], tetraphenylene and its derivatives have found broad applications in materials science [5][6][7][8][9][10][11], supramolecular chemistry [12][13][14][15][16][17][18], and asymmetric catalysis [19][20][21]. Since Rapson and co-workers reported the first
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