Addition of trifluoromethyltrimethylsilane to acyl phosphonates: Synthesis of TMS-Protected 1-alkyl-1-trifluoromethyl-1-hydroxyphosphonates and 1-aryldifluoroethenyl phosphates

Demir, Ayhan Sıtkı
Eymur, Serkan
Addition reactions of nucleophilic CF3TMS to acyl phosphonates were investigated. Various acyl phosphonates reacted readily with CF3TMS in the presence of K2CO3 in DMF at rt to give 1-alkyl-2,2,2-trifluoro-1-trimethylsilyloxyethylphosphonate in 70−90% yields. When benzoyl phosphonates were used as starting material, after addition of CF3, the formed alcoholate undergoes phosphonate−phosphate rearrangement to form the acyl anion, followed by elimination of F- to give 1-aryldifluoroethenyl phosphates in 87−97% yields. As a representative example, vinylphosphate 6a was converted into 2,2-difluoro-1-phenylethanone 7 with 6 N HCl/EtOH/reflux or CAN/NaOH/MeOH/0 °C in 82−90% yields.


Synthesis of 1,2,3,5- tetrasubstituted pyrrole derivatives via 5-exo-dig type cyclization and stereoselective functionalisation of ferrocene derivatives
Kayalar, Metin; Demir, Ayhan Sıtkı; Department of Chemistry (2005)
A convenient and new method for the synthesis of 1,2,3,5-tetrasubstituted pyrrole derivatives starting from 1,3,-dicarbonyl compounds through acid catalyzed cyclization reaction is described. Alkylation of 1,3-dicarbonyl compound with propargyl bromide followed by one step cyclization with the introduction of primary amines in the presence of catalytic amount of triflouroacetic acid (TFA) affords the corresponding pyrrole derivatives in high yields. The investigations on the studies of developing a new meth...
Incorporation of an allene unit into alpha-pinene: Generation of the cyclic allene 2,7,7-trimethylbicyclo[4.1.]octa-2,3-diene and its dimerization
Azizoglu, A; Ozen, R; Hokelek, T; Balcı, Metin (American Chemical Society (ACS), 2004-02-20)
The reaction of etheral methyllithium with 3,3-dibromo-2,7,7-trimethyl-tricyclo[,4)] octane (2) was investigated. The generated carbene 12 undergoes intramolecular C-H insertion to provide the tetracyclic hydrocarbon 3 and the bicyclic allene 15, which undergoes [2 + 2] cyclodimerization. The structures of the formed allene dimers 16, 17, and 18 were elucidated by spectral means. The activation barriers for all possible C-H insertion products 3, 13, and 14 and the allene 15 were investigated by us...
Oxidation of Primary Alcohols to Aldehydes with N-Halamine-Containing Polymers
Akdağ, Akın; Öztürk, Perihan (Georg Thieme Verlag KG, 2013-11-12)
Polymeric N-halamines have been previously employed for organic reactions such as sulfide oxidation. In the present study, we employed polymeric N-halamines to oxidize primary alcohols selectively to the corresponding aldehydes in excellent yields. After reaction, the polymers can be recycled and then reused for the next reaction process.
Addition of 1,3-dicarbonyl compounds to the cycloheptatriene derivatives
Südemen, M. Burak; Balcı, Metin; Department of Chemistry (2009)
The one electron oxidant Mn(OAc)3 has been used for years for the oxidative addition of 1,3-dicarbonyls to alkenes to give dihydrofuranes. Since cycloheptatriene is in equilibrium with its valance isomer norcaradiene, it will be interesting to study the reaction of CHT derivatives with Mn(OAc)3 in the presence of 1,3-dicarbonyls. In our research, we have observed that unsubstituted cycloheptatriene gave CHT based products. However, when electron withdrawing -CN group was attached to C-7 position of CHT we o...
Transition structures, energetics, and nucleus-independent chemical shifts for 6 pi electrocyclizations of dienylketenes to cyclohexadienones: A DFT study
Zora, Metin (American Chemical Society (ACS), 2004-03-19)
6pi electrocyclizations of dienylketenes to 2,4-cyclohexadienones have been investigated at the (U)B3LYP/6-31G* level and found to be a favored and exothermic process for most dienylketenes. As evidenced by calculations, dienylketene cyclizations proceed via a pseudopericyclic process. If the terminal double bond of dienylketenes is embedded into a benzenoid-type aryl moiety, the partial or complete loss of aromaticity, as indicated by NICS values, increases the activation barrier and makes the reaction les...
Citation Formats
A. S. Demir and S. Eymur, “Addition of trifluoromethyltrimethylsilane to acyl phosphonates: Synthesis of TMS-Protected 1-alkyl-1-trifluoromethyl-1-hydroxyphosphonates and 1-aryldifluoroethenyl phosphates,” JOURNAL OF ORGANIC CHEMISTRY, pp. 8527–8530, 2007, Accessed: 00, 2020. [Online]. Available: