Properties of PTFE tape as a semipermeable membrane in fluorous reactions

• Brendon A. Parsons,
• Olivia Lin Smith,
• Myeong Chae and
• Veljko Dragojlovic

Beilstein J. Org. Chem. 2015, 11, 980–993, doi:10.3762/bjoc.11.110

• tape phase-vanishing reaction (PV-PTFE), a delivery tube sealed with PTFE tape is inserted into a vessel which contains the substrate. The reagent diffuses across the PTFE tape barrier into the reaction vessel. PTFE co-polymer films have been found to exhibit selective permeability towards organic

• simultaneously carry out the reaction and separate the products [6][7]. Soon after, Ryu and Curran reported the fluorous phase-vanishing (PV) method, which unlike the triphasic fluorous reaction, does not require the use of fluorous reactants [8]. In the course of the reaction, one phase vanishes, hence the name

• was followed by numerous improved and modified designs including a quadraphasic/tetraphasic PV reaction [10], a photochemical PV reaction [11][12], a stacked phase-vanishing reaction [13], a PV reaction on neat substrates [11][14][15][16] and, most recently, a Grignard reaction [17]. Jana and Verkade

Solvent-free phase-vanishing reactions with PTFE (Teflon^®) as a phase screen

• Kevin Pels and
• Veljko Dragojlovic

Beilstein J. Org. Chem. 2009, 5, No. 75, doi:10.3762/bjoc.5.75

• Kevin Pels Veljko Dragojlovic Wilkes Honors College of Florida Atlantic University, 5353 Parkside Drive, Jupiter, FL 33458, USA 10.3762/bjoc.5.75 Abstract In a solvent-free phase-vanishing reaction with PTFE (polytetrafluoroethylene, Teflon®) tape as the phase screen, a thermometer adapter is

• purity. Keywords: bromination; phase-vanishing; PTFE; solvent-free; stilbene; Findings Phase-vanishing (PV) reactions are triphasic reactions, which involve a reagent, a liquid perfluoroalkane and a substrate [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. In a test tube, a liquid

Phase- vanishing halolactonization of neat substrates

• Nicole Windmon and
• Veljko Dragojlovic

Beilstein J. Org. Chem. 2008, 4, No. 29, doi:10.3762/bjoc.4.29

• Nicole Windmon Veljko Dragojlovic Department of Chemistry, Florida Atlantic University, 777 Glades Road, Boca Raton, Florida 33431, USA Wilkes Honors College of Florida Atlantic University, 5353 Parkside Drive, Jupiter, Florida, 33458, USA. 10.3762/bjoc.4.29 Abstract Phase-vanishing reactions are

• triphasic reactions which involve a reagent, a liquid perfluoroalkane as a phase screen and a substrate. The perfluoroalkane does not dissolve any of the reactants and is used to separate them. Halolactonization of neat substrates under phase-vanishing conditions avoids use of both solvents and basic

• reaction conditions. Both γ,δ-alkenoic acids as well as the corresponding methyl esters are suitable substrates for phase-vanishing halolactonizations. The reaction works well both on solid and liquid substrates and the products are obtained in good to excellent yields, particularly in the case of rigid