Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives

• Jan Bartáček,
• Karel Chlumský,
• Jan Mrkvička,
• Lucie Paloušová,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2024, 20, 684–691, doi:10.3762/bjoc.20.62

• also tested in asymmetric aldol reactions. Under the optimised reaction conditions, aldol products with enantioselectivities of up to 91% ee were obtained. Keywords: asymmetric aldol reaction; asymmetric Henry reaction; chiral ligands; enantioselective catalysis; imidazolidine derivatives

• pyridine derivative [5] (see Supporting Information File 1, part S5); the ee values were overall high (74–92%), however, a little bit lower than those achieved by the complex of ligand IIIa (Δ 1–15% ee). Further, the copper(II) complex of ligand IV were also tested for asymmetric Henry reaction. The ligand

• structures for the Henry reaction. The preparation of 5-isopropyl-5-methyl-2-(pyridin-2-yl)imidazolidin-4-one derivatives and their application in asymmetric Henry reaction [5]. Asymmetric Henry reactions of various aldehydes with nitromethane catalysed by copper(II) complexes of ligands Ia–c. Asymmetric

The asymmetric Henry reaction as synthetic tool for the preparation of the drugs linezolid and rivaroxaban

• Martin Vrbický,
• Karel Macek,
• Jaroslav Pochobradský,
• Jan Svoboda,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2022, 18, 438–445, doi:10.3762/bjoc.18.46

• of these drugs was studied in detail. Highly enantioselective catalysts were tested in the key step of the synthetic procedure, i.e., the asymmetric Henry reaction, under different reaction conditions, using several starting aldehydes. The corresponding nitroaldols as chiral intermediates in the

• syntheses of these drugs were obtained in high yields and enantiomeric excesses of up to 91% ee. Keywords: asymmetric Henry reaction; enantioselective catalysis; linezolid; oxazolidine-2-one derivatives; rivaroxaban; Introduction Oxazolidine-2-one derivatives represent an important branch of

• -1,2-diol, etc.) [11]. Beside this, approaches in which asymmetric synthesis is included are also applicable. Recently, the utilization of an asymmetric Henry reaction for the preparation of two oxazolidine-type drugs, namely linezolid (1) and rivaroxaban (2), has been described [12][13]. These

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• achieve reusable catalysts for batch and continuous-flow studies. Inherently chiral calix[4]arene-based phase-transfer catalysts. Calix[4]arene-amides used as phase-transfer catalysts. Proposed transition state model of asymmetric Henry reaction. Structure of inherently chiral oxazoline calix[4]arenes

• inherently chiral calix[4]arenes 20a/20b substituted at the lower rim. Reaction conditions: (i) TsOCH2CH2OCH3/NaH, THF; (ii) t-BuOK, H2O/BuOH/DMSO; (iii) HNEt2, HBTU, CH2Cl2; (iv) LiAlH4/THF. Asymmetric Henry reaction between 21 and 22 catalyzed by 20a/20b. Synthesis of enantiomerically pure

Synthesis of chiral 3-substituted 3-amino-2-oxindoles through enantioselective catalytic nucleophilic additions to isatin imines

• Hélène Pellissier

Beilstein J. Org. Chem. 2018, 14, 1349–1369, doi:10.3762/bjoc.14.114

• -Henry reactions The catalytic asymmetric Henry reaction, also known as catalytic asymmetric nitroaldol reaction, constitutes a useful synthetic methodology towards chiral β-nitro alcohols [69][70]. This reaction and related aza-Henry reactions involving imines have been promoted by both metal catalysts

Organocatalytic asymmetric Henry reaction of 1H-pyrrole-2,3-diones with bifunctional amine-thiourea catalysts bearing multiple hydrogen-bond donors

• Ming-Liang Zhang,
• Deng-Feng Yue,
• Zhen-Hua Wang,
• Yuan Luo,
• Xiao-Ying Xu,
• Xiao-Mei Zhang and
• Wei-Cheng Yuan

Beilstein J. Org. Chem. 2016, 12, 295–300, doi:10.3762/bjoc.12.31

• 100049, China 10.3762/bjoc.12.31 Abstract For the first time, a catalytic asymmetric Henry reaction of 1H-pyrrole-2,3-diones was achieved with a chiral bifunctional amine-thiourea as a catalyst possessing multiple hydrogen-bond donors. With this developed method, a range of 3-hydroxy-3-nitromethyl-1H

• by the multiple hydrogen bonds of the catalyst. Thus, the nitro enolate attacks the keto carbonyl group of 1H-pyrrole-2,3-diones (to the si-face) to furnish the corresponding product with S-configuration (Figure 2). Conclusion In conclusion, we have developed an asymmetric Henry reaction of 1H

• currently underway. The X-ray structure of compound 4i. A proposed transition state for the asymmetric Henry reaction. The strategy to construct chiral 3-substituted-3-hydroxy-1H-pyrrol-2(3H)-ones. Screening of the catalysts and solvents.a Further optimization of conditions.a Scope of the reaction.a