Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

• catalysis and proceed through a double addition mechanism. In 2011, Mikami et al. developed a catalytic asymmetric oxetane synthesis from silyl enol ethers 89 and trifluoropyruvate 90 using a chiral Cu(II) complex (Scheme 24) [67]. Besides excellent yields, they also observed very high cis/trans ratios and

Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates

• Judit Hostalet-Romero,
• Laura Carceller-Ferrer,
• Gonzalo Blay,
• Amparo Sanz-Marco,
• José R. Pedro and
• Carlos Vila

Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41

• , the reaction yielded compound 7 as the final product. Once the starting materials were synthesized, we focused our attention on the optimization of the reaction conditions. We chose the reaction between 4-cyclohexenyl-5-aminopyrazole (3aa) and methyl trifluoropyruvate (4a) for the optimization studies

• results in terms of yield and diastereoselectivity, when methyl or ethyl trifluoropyruvate were used as reactants. Next, we tested the influence of different substituents on the cyclohexenyl ring of the aminopyrazole 3, observing lower yields for homoallylic alcohols 5baa and 5caa in both conditions used

• . Considering the high diastereoselectivity observed both in the presence and absence of the squaramide catalyst, we propose a plausible mechanism (Scheme 3) that involves hydrogen bonding activation of the methyl trifluoropyruvate by the NH₂ group of the aminopyrazole. This interaction directs the attack of

Ring opening of photogenerated azetidinols as a strategy for the synthesis of aminodioxolanes

• Henning Maag,
• Daniel J. Lemcke and
• Johannes M. Wahl

Beilstein J. Org. Chem. 2024, 20, 1671–1676, doi:10.3762/bjoc.20.148

• to form stable hemiacetals [35][36][37][38][39][40]. While we were unable to isolate ring-opened products from trifluoroacetophenone (12), chloral (13), and indane-1,2,3-trione (14), ethyl trifluoropyruvate (15) furnished the desired dioxolane 16, which was isolated as a mixture of diastereomers in

Fluorinated phenylalanines: synthesis and pharmaceutical applications

• Laila F. Awad and
• Mohammed Salah Ayoup

Beilstein J. Org. Chem. 2020, 16, 1022–1050, doi:10.3762/bjoc.16.91

• synthesis from ethyl trifluoropyruvate hemiketal The reaction of ethyl trifluoropyruvate hemiketal 130 with thionyl chloride in pyridine afforded the chlorinated derivative 131, which upon treatment with zinc powder in DMF, afforded the dihalogenated olefin 132. The substitution of one fluorine atom in 132

Enantioselective Diels–Alder reaction of anthracene by chiral tritylium catalysis

• Qichao Zhang,
• Jian Lv and
• Sanzhong Luo

Beilstein J. Org. Chem. 2019, 15, 1304–1312, doi:10.3762/bjoc.15.129

• found that less than 6% of trityl phosphate (TP) dissociated to trityl cations in the presence of a polar substrate such trifluoropyruvate [20]. In order to improve the efficiency of the dissociation, we started by first studying the properties of tritylium salts with a weakly coordinating metal-based

Copper-catalyzed asymmetric methylation of fluoroalkylated pyruvates with dimethylzinc

• Kohsuke Aikawa,
• Kohei Yabuuchi,
• Kota Torii and
• Koichi Mikami

Beilstein J. Org. Chem. 2018, 14, 576–582, doi:10.3762/bjoc.14.44

• copper. Keywords: asymmetric methylation; chiral phosphine ligand; copper catalyst; dimethylzinc; trifluoropyruvate; Introduction The introduction of fluorine atoms into organic compounds plays an important role in the discovery of lead candidates with unique biological and physicochemical properties

• , many researchers including us have studied the catalytic asymmetric synthesis of optically active α-trifluoromethylated tertiary alcohols [7][8]. In these cases, one of commercially available and versatile trifluoromethyl sources, trifluoropyruvate, has been utilized for a variety of catalytic

• asymmetric carbon–carbon bond forming reactions, providing efficiently α-trifluoromethylated tertiary alcohols in high enantioselectivities [9][10][11][12][13][14][15][16][17][18][19]. Over the past decade we have also investigated several catalytic asymmetric reactions using trifluoropyruvate as an

The first organocatalytic carbonyl- ene reaction: isomerisation- free C-C bond formations catalysed by H-bonding thio- ureas

• Matthew L. Clarke,
• Charlotte E. S. Jones and
• Marcia B. France

Beilstein J. Org. Chem. 2007, 3, No. 24, doi:10.1186/1860-5397-3-24

• polymerised under the reaction conditions. An exception was the ene reaction of ethyl trifluoropyruvate 2 with alkenes which actually took place very readily, although sometimes accompanied by isomerisation and other side products. This type of ene reaction has recently been explored by other groups using Pd

• , Ni and Pt catalysts.[7][8] The importance of such reactions is derived from the ever-increasing occurrence of trifluoromethyl substituents in drugs and biologically active compounds.[9][10] Given that trifluoropyruvate ene reactions seemingly have a low activation barrier, and as part of our ongoing

• our knowledge, the first example of an organocatalytic carbonyl ene reaction. [17] Findings We first carried out a thermal ene reaction of α-methyl styrene 1 with ethyl trifluoropyruvate under microwave heating to produce racemic product 3 (Scheme 1). This reaction was accompanied by several side