Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines

• Sergio Torres-Oya and
• Mercedes Zurro

Beilstein J. Org. Chem. 2024, 20, 3221–3255, doi:10.3762/bjoc.20.268

• enantiomeric ratio retained. In September 2023, Lan, Huang, Yan and co-workers reported a phosphoric acid-catalyzed enantioselective reaction of acyclic α,β-unsaturated imines and azlactones enabling through an aza-inverse electron demand Diels–Alder reaction, the synthesis of chiral 3‑amino-δ-lactams (Scheme

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• -trifluoromethylamine derivatives of high molecular complexity (Scheme 28). The process involves a highly enantioselective reaction of the isatin-derived Morita–Baylis–Hillman carbonate 137 with a novel α-CF3-substituted imine 136, derived from inexpensive benzothiophene-2,3-dione. A C2-symmetrical cinchona-derived

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

• Stefan P. Schmid,
• Leon Schlosser,
• Frank Glorius and
• Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• [69]. Herein, Li and co-workers developed a new asymmetric synthesis of atropisomeric pyrazole derivatives 56 via an enantioselective reaction of azonaphthalene 54 with pyrazolone 55 using 5 mol % chiral phosphoric acid CPA 16. Substrates bearing electron-donating and electron-withdrawing groups gave

• materials and supramolecules. Important chiral phosphoric acid scaffolds used in this review. Atroposelective aryl–aryl-bond formation by employing a facile [3,3]-sigmatropic rearrangement. Atroposelective synthesis of axially chiral biaryl amino alcohols 5. The enantioselective reaction of quinone and 2

• naphthylindoles [65]. Enantioselective synthesis of axially chiral 3,3’-bisindoles [66]. Atroposelective synthesis of 3,3’-bisiindoles bearing axial and central chirality. Enantioselective synthesis of axially chiral 3,3’-bisindoles bearing single axial chirality. Enantioselective reaction of azonaphthalenes with

Asymmetric organocatalyzed synthesis of coumarin derivatives

• Natália M. Moreira,
• Lorena S. R. Martelli and
• Arlene G. Corrêa

Beilstein J. Org. Chem. 2021, 17, 1952–1980, doi:10.3762/bjoc.17.128

• gram-scale experiment, affording the desired product 21a with excellent yield and ee (Scheme 6b). Ren et al. reported an enantioselective reaction of cyclopent-2-enone-derived Morita–Baylis–Hillman (MBH) alcohols 24 with 4-hydroxycoumarins 1 catalyzed by a chiral primary amine derived from

• cascade reaction. Total synthesis of (+)-smyrindiol (17). Michael addition of 4-hydroxycoumarin (1) to enones 2 through a bifunctional modified binaphthyl organocatalyst 18. Michael addition of ketones 20 to 3-aroylcoumarins 19 using a cinchona alkaloid-derived primary amine catalyst 22. Enantioselective

• reaction of cyclopent-2-enone-derived MBH alcohols 24 with 4-hydroxycoumarins 1. Sequential Michael addition/hydroalkoxylation one-pot approach to annulated coumarins 28 and 30. Michael addition of 4-hydroxycoumarins 1 to enones 2 using a binaphthyl diamine catalyst 31. Asymmetric Michael addition of 4

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

• enantioselectivities (14 examples, up to 98:2 er). The quantum yield of the enantioselective reaction could not be ascertained due to the reaction being heterogenous, but the quantum yield for the racemic variant using an achiral base was >1 (Φ = 1.2), supporting the proposed radical chain process. While these results

Copper-catalyzed enantioselective conjugate reduction of α,β-unsaturated esters with chiral phenol–carbene ligands

• Shohei Mimura,
• Sho Mizushima,
• Yohei Shimizu and
• Masaya Sawamura

Beilstein J. Org. Chem. 2020, 16, 537–543, doi:10.3762/bjoc.16.50

• catalyst worked well for various (Z)-isomer substrates. Opposite enantiomers were obtained from (Z)- and (E)-isomers, with a higher enantiomeric excess from the (Z)-isomer. Keywords: catalyst; chiral NHC; conjugate reduction; copper catalysis; enantioselective reaction; Introduction Since the leading

New α- and β-cyclodextrin derivatives with cinchona alkaloids used in asymmetric organocatalytic reactions

• Iveta Chena Tichá,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2019, 15, 830–839, doi:10.3762/bjoc.15.80

• enantioselective reaction (Table 3, entry 29) and this derivative was also tested in the AAA reaction with (1S)-10-camphorsulfonic acid (CSA) according to the original procedure [38], in which the cocatalyst (1S)-CSA enhanced the efficiency of dimeric cinchona alkaloids (Table 3, entry 30). However, there was no

Enantioselective phase-transfer catalyzed alkylation of 1-methyl-7-methoxy-2-tetralone: an effective route to dezocine

• Ruipeng Li,
• Zhenren Liu,
• Liang Chen,
• Jing Pan and
• Weicheng Zhou

Beilstein J. Org. Chem. 2018, 14, 1421–1427, doi:10.3762/bjoc.14.119

• enantiocontrol (Table 1, entries 5 and 6). Fortunately, the p-CF3 derivative (C7) promoted the reaction to give a enantiomeric ratio of 83:17 (Table 1, entry 7). These findings suggested that the presence of electron-withdrawing groups on the benzyl group was favourable for the enantioselective reaction except

Regioselective decarboxylative addition of malonic acid and its mono(thio)esters to 4-trifluoromethylpyrimidin-2(1H)-ones

• Sergii V. Melnykov,
• Andrii S. Pataman,
• Yurii V. Dmytriv,
• Svitlana V. Shishkina,
• Mykhailo V. Vovk and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2017, 13, 2617–2625, doi:10.3762/bjoc.13.259

• reasonable conversion with TEA as catalyst. Quinine and QT were again found to be ineffective to promote the enantioselective reaction (Table 3, entries 4 and 5). In contrast to the reaction with malonic acid under similar conditions, just trace amounts of regioisomeric Mannich-type adduct 7a were detected

Synergistic chiral iminium and palladium catalysis: Highly regio- and enantioselective [3 + 2] annulation reaction of 2-vinylcyclopropanes with enals

• Haipan Zhu,
• Peile Du,
• Jianjun Li,
• Ziyang Liao,
• Guohua Liu,
• Hao Li and
• Wei Wang

Beilstein J. Org. Chem. 2016, 12, 1340–1347, doi:10.3762/bjoc.12.127

• and methyl vinyl ketone and α,β-unsaturated esters [44]. Trost and co-workers orchestrated the only example of the enantioselective reaction of D–A cyclopropanes with C=C double bonds with Meldrum’s acid and alkylidenes or azlactone alkylidenes, catalyzed by the chiral Trost Pd(0)-complexes [45

(Thio)urea-mediated synthesis of functionalized six-membered rings with multiple chiral centers

• Giorgos Koutoulogenis,
• Nikolaos Kaplaneris and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2016, 12, 462–495, doi:10.3762/bjoc.12.48

• -workers disclosed the first enantioselective reaction of α-cyanoketones 118 to α,β-unsaturated trifluoromethyl ketones 119, utilizing a novel organocatalyst that they developed containing a piperazine moiety (S)-120 (Scheme 38) [58]. The reaction proceeded through a Michael addition to the unsaturated

Cupreines and cupreidines: an established class of bifunctional cinchona organocatalysts

• Laura A. Bryant,
• Rossana Fanelli and
• Alexander J. A. Cobb

Beilstein J. Org. Chem. 2016, 12, 429–443, doi:10.3762/bjoc.12.46

• -formylindoles 98 and nitroolefins 41 to generate the corresponding tricyclic adducts 99 using cupreidine derivative CPD-30 (Scheme 23). Although the substrate scope for the enantioselective reaction is limited, the diastereoselectivities are reasonable, and the enantioselectivities are excellent. Other

Efficient synthesis of dihydropyrimidinones via a three-component Biginelli-type reaction of urea, alkylaldehyde and arylaldehyde

• Haijun Qu,
• Xuejian Li,
• Fan Mo and
• Xufeng Lin

Beilstein J. Org. Chem. 2013, 9, 2846–2851, doi:10.3762/bjoc.9.320

• crystal structure of 4a. Scope of the enantioselective reaction. Reaction conditions: 5a (10 mol %, 0.02 mmol), 1 (0.2 mmol), 2 (0.2 mmol), 3 (0.3 mmol), MS 4 Å (0.1 g), toluene (1 mL), rt, 2 days. Isolated Yields were given. The ee’s were determined by chiral HPLC. Possible mechanism. Optimization of

Synthetic scope and DFT analysis of the chiral binap–gold(I) complex-catalyzed 1,3-dipolar cycloaddition of azlactones with alkenes

• María Martín-Rodríguez,
• Luis M. Castelló,
• Carmen Nájera,
• José M. Sansano,
• Olatz Larrañaga,
• Abel de Cózar and
• Fernando P. Cossío

Beilstein J. Org. Chem. 2013, 9, 2422–2433, doi:10.3762/bjoc.9.280

• gold(I) catalyst, promoted the enantioselective reaction although with lower efficiency (Table 1, entries 17 and 18) [32]. The scope of the reaction was next surveyed. Firstly, azlactone 5a was allowed to react with several maleimides (Scheme 2, and Table 2, entries 1–10). NPM and 4

Natural products in synthesis and biosynthesis

• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 1897–1898, doi:10.3762/bjoc.9.223

• 1920s and its later enhancement into an enantioselective reaction by the development of chiral catalysts. But a Diels–Alder reaction also occurs in the biosynthesis of lovastatin and is likely catalysed by a Diels–Alderase [5], a natural analogue of man-made chiral catalysts! Beyond such fascinating

Enantioselective synthesis of planar chiral ferrocenes via palladium-catalyzed annulation with diarylethynes

• Yan-Chao Shi,
• Rong-Fei Yang,
• De-Wei Gao and
• Shu-Li You

Beilstein J. Org. Chem. 2013, 9, 1891–1896, doi:10.3762/bjoc.9.222

• -catalyzed direct coupling of N,N-disubstituted aminomethylferrocenes with diarylethyne into an enantioselective reaction. Then planar chiral ferrocenyl P,N-ligands with a large substituent could be readily synthesized. In this paper, we report the results from this study. Results and Discussion We initiated

Cascade radical reaction of substrates with a carbon–carbon triple bond as a radical acceptor

• Hideto Miyabe,
• Ryuta Asada and
• Yoshiji Takemoto

Beilstein J. Org. Chem. 2013, 9, 1148–1155, doi:10.3762/bjoc.9.128

• , respectively. However, the reaction with a bulky tert-butyl radical did not proceed effectively, probably due to side reactions such as polymerization. We finally investigated the enantioselective reaction of internal alkynes 14 and 16 (Scheme 7). The reaction of 14 proceeded with good enantioselectivities

• substrates and the stereochemistry of cyclization. Substrates for testing the cascade transformation. E/Z-selectivity of 9Aa–Ca. Model for the enantioselective reaction. Effect of hydroxamate ester on intermolecular C–C bond-forming reactions. Cascade radical addition–cyclization–trapping reaction of 5 and

Reactions of salicylaldehyde and enolates or their equivalents: versatile synthetic routes to chromane derivatives

• Ishmael B. Masesane and
• Zelalem Yibralign Desta

Beilstein J. Org. Chem. 2012, 8, 2166–2175, doi:10.3762/bjoc.8.244

• 27. Although Shanti and co-workers used a chiral catalyst, no data was provided on the stereoselectivity of this reaction. In a study related to that of Shanti and co-workers, Yang and co-workers used chiral amine-thiourea catalyst 31 in a three-component enantioselective reaction of salicylaldehyde

Rh(III)-catalyzed directed C–H bond amidation of ferrocenes with isocyanates

• Satoshi Takebayashi,
• Tsubasa Shizuno,
• Takashi Otani and
• Takanori Shibata

Beilstein J. Org. Chem. 2012, 8, 1844–1848, doi:10.3762/bjoc.8.212

• example of catalytic methods to construct planar chiral ferrocenes. We are currently investigating an enantioselective reaction. The ORTEP drawing of 3c with 30% probability ellipsoids, and Flack absolute structure parameter of 0.003(12). Screening of catalysts. Scope of isocyanates. Diastereoselective