Ring-Opening of 1-CF3-Substituted Epoxy Ethers with Carboxylic, Thiocarboxylic, and Phosphinic Acids in Basic Medium and in Hexafluoro-2-propanol

Abstract

Keywords: Epoxy ethers / Fluorine / Hydrogen bonds / Trifluoromethyl ketones / Ring openingRing-opening of 1-CF 3 -substituted epoxy ethers with carboxylic acids was achieved in Et 3 N as solvent, and α-CF 3 -substituted acyloins and corresponding esters were obtained in good yields. In hexafluoro-2-propanol (HFIP) as solvent, the carboxylic acids acted as nucleophiles, and α-carbonyloxy trifluoromethyl ketones were isolated in good yields. After reduction, CF 3 -substituted glycols were obtained as monoes-

Preparation of 10-Trifluoromethyl Artemether and Artesunate. Influence of Hexafluoropropan-2-ol on Substitution Reaction

“…All these properties contribute to modify the course and the rate of solvolysis reactions when HFIP is used as solvent . They have also been exploited in various other reactions, such as hydrogen peroxide activation, oxirane ring opening, Nazarov cyclization, or Michael reaction …”

“…11 All these properties contribute to modify the course and the rate of solvolysis reactions when HFIP is used as solvent. 14 They have also been exploited in various other reactions, such as hydrogen peroxide activation, oxirane ring opening, 15 Nazarov cyclization, 16 or Michael reaction. 17 Experiments under various conditions using different ratios of HFIP/MeOH or HFIP/CH 2 Cl 2 /MeOH allowed selecting the following best conditions for the reaction of 4 with MeOH: 10 equiv of MeOH and 5 equiv of HFIP in a dichloromethane solution at room temperature.…”

Preparation of 10-Trifluoromethyl Artemether and Artesunate. Influence of Hexafluoropropan-2-ol on Substitution Reaction

“…All these properties contribute to modify the course and the rate of solvolysis reactions when HFIP is used as solvent . They have also been exploited in various other reactions, such as hydrogen peroxide activation, oxirane ring opening, Nazarov cyclization, or Michael reaction …”

“…11 All these properties contribute to modify the course and the rate of solvolysis reactions when HFIP is used as solvent. 14 They have also been exploited in various other reactions, such as hydrogen peroxide activation, oxirane ring opening, 15 Nazarov cyclization, 16 or Michael reaction. 17 Experiments under various conditions using different ratios of HFIP/MeOH or HFIP/CH 2 Cl 2 /MeOH allowed selecting the following best conditions for the reaction of 4 with MeOH: 10 equiv of MeOH and 5 equiv of HFIP in a dichloromethane solution at room temperature.…”

Solvent-Free Tandem Reaction of P(O)–OH and an Epichlorohydrocarbon for Controllable O-Alkylation through a Ring-Opening and Annulation Process

“…20 Because the amounts of the dechlorinated products gradually increased on prolongation of the reaction time or on an increase in the temperature, and because three-and four-membered rings are unstable, the O-alkylation probably proceeds through a tandem reaction involving a ringopening and an intramolecular annulation process. [21][22][23][24][25][26][27] Attempts to react 2-(chloromethyl)-1,3-dioxolane (2d), containing a five-membered ring, or 2-(chloromethyl)tetrahydro-2H-pyran (2e), containing a six-membered ring, with 1a resulted in no ring-opened or dechlorinated products being detected, probably because of the stability of fiveand six-membered rings (Equation 2). This document was downloaded for personal use only.…”

Petasis three-component reaction accelerated by trifluoroacetic acid: synthesis of indoline-derived glycines

“…1 H NMR(400MHz, DMSO-d 6 ): δ=8.00(1H, m), 7.86(1H, s), 7.26(4H, m), 6.70(1H, d, J=8.94Hz), 5.71(1H, s), 3.81(1H, m), 3.21(1H, m), 3.00(2H, m), 2.32(3H, s); 13 C NMR (400MHz, DMSO-d6): δ=171. 16…”

Preparation of 10-Trifluoromethyl Artemether and Artesunate. Influence of Hexafluoropropan-2-ol on Substitution Reaction

“…All these properties contribute to modify the course and the rate of solvolysis reactions when HFIP is used as solvent . They have also been exploited in various other reactions, such as hydrogen peroxide activation, oxirane ring opening, Nazarov cyclization, or Michael reaction …”

“…11 All these properties contribute to modify the course and the rate of solvolysis reactions when HFIP is used as solvent. 14 They have also been exploited in various other reactions, such as hydrogen peroxide activation, oxirane ring opening, 15 Nazarov cyclization, 16 or Michael reaction. 17 Experiments under various conditions using different ratios of HFIP/MeOH or HFIP/CH 2 Cl 2 /MeOH allowed selecting the following best conditions for the reaction of 4 with MeOH: 10 equiv of MeOH and 5 equiv of HFIP in a dichloromethane solution at room temperature.…”

Solvent-Free Tandem Reaction of P(O)–OH and an Epichlorohydrocarbon for Controllable O-Alkylation through a Ring-Opening and Annulation Process

“…20 Because the amounts of the dechlorinated products gradually increased on prolongation of the reaction time or on an increase in the temperature, and because three-and four-membered rings are unstable, the O-alkylation probably proceeds through a tandem reaction involving a ringopening and an intramolecular annulation process. [21][22][23][24][25][26][27] Attempts to react 2-(chloromethyl)-1,3-dioxolane (2d), containing a five-membered ring, or 2-(chloromethyl)tetrahydro-2H-pyran (2e), containing a six-membered ring, with 1a resulted in no ring-opened or dechlorinated products being detected, probably because of the stability of fiveand six-membered rings (Equation 2). This document was downloaded for personal use only.…”

Petasis three-component reaction accelerated by trifluoroacetic acid: synthesis of indoline-derived glycines

“…1 H NMR(400MHz, DMSO-d 6 ): δ=8.00(1H, m), 7.86(1H, s), 7.26(4H, m), 6.70(1H, d, J=8.94Hz), 5.71(1H, s), 3.81(1H, m), 3.21(1H, m), 3.00(2H, m), 2.32(3H, s); 13 C NMR (400MHz, DMSO-d6): δ=171. 16…”

Preparation of 10-Trifluoromethyl Artemether and Artesunate. Influence of Hexafluoropropan-2-ol on Substitution Reaction

“…All these properties contribute to modify the course and the rate of solvolysis reactions when HFIP is used as solvent . They have also been exploited in various other reactions, such as hydrogen peroxide activation, oxirane ring opening, Nazarov cyclization, or Michael reaction …”

“…11 All these properties contribute to modify the course and the rate of solvolysis reactions when HFIP is used as solvent. 14 They have also been exploited in various other reactions, such as hydrogen peroxide activation, oxirane ring opening, 15 Nazarov cyclization, 16 or Michael reaction. 17 Experiments under various conditions using different ratios of HFIP/MeOH or HFIP/CH 2 Cl 2 /MeOH allowed selecting the following best conditions for the reaction of 4 with MeOH: 10 equiv of MeOH and 5 equiv of HFIP in a dichloromethane solution at room temperature.…”

Solvent-Free Tandem Reaction of P(O)–OH and an Epichlorohydrocarbon for Controllable O-Alkylation through a Ring-Opening and Annulation Process

“…20 Because the amounts of the dechlorinated products gradually increased on prolongation of the reaction time or on an increase in the temperature, and because three-and four-membered rings are unstable, the O-alkylation probably proceeds through a tandem reaction involving a ringopening and an intramolecular annulation process. [21][22][23][24][25][26][27] Attempts to react 2-(chloromethyl)-1,3-dioxolane (2d), containing a five-membered ring, or 2-(chloromethyl)tetrahydro-2H-pyran (2e), containing a six-membered ring, with 1a resulted in no ring-opened or dechlorinated products being detected, probably because of the stability of fiveand six-membered rings (Equation 2). This document was downloaded for personal use only.…”

Petasis three-component reaction accelerated by trifluoroacetic acid: synthesis of indoline-derived glycines

“…1 H NMR(400MHz, DMSO-d 6 ): δ=8.00(1H, m), 7.86(1H, s), 7.26(4H, m), 6.70(1H, d, J=8.94Hz), 5.71(1H, s), 3.81(1H, m), 3.21(1H, m), 3.00(2H, m), 2.32(3H, s); 13 C NMR (400MHz, DMSO-d6): δ=171. 16…”