New method of preparation of C2F5Li and its reactions with cyclic imines and lactims: Synthesis of α-pentafluoroethyl proline

Shevchenko, Nikolay E.; Nenajdenko, Valentine G.; Röschenthaler, Gerd‐Volker

doi:10.1016/j.jfluchem.2008.01.013

Cited by 58 publications

(20 citation statements)

References 41 publications

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“…[17] It was generated in situ according to a literature method [9] and subsequently treated with Cl 2 PNEt 2 . The product, (C 2 F 5 ) 2 PNEt 2 , was isolated by vacuum distillation as a colourless liquid.…”

Section: Preparation Of Bis(pentafluoroethyl)phosphane Derivativesmentioning

confidence: 99%

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Functionalized Bis(pentafluoroethyl)phosphanes: Improved Syntheses and Molecular Structures in the Gas Phase

et al. 2013

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(C2F5)2PNEt2 represents an excellent starting material for the selective synthesis of bis(pentafluoroethyl)phosphane derivatives. The moderately air‐sensitive aminophosphane is accessible on a multi‐gram scale by treating Cl2PNEt2 with C2F5Li. Treatment with gaseous HCl or HBr yielded the corresponding phosphane halides (C2F5)2PCl and the so far unknown (C2F5)2PBr in good yields. The hitherto unknown (C2F5)2PF was obtained by treating (C2F5)2PBr with excess antimony trifluoride. Treatment of (C2F5)2PCl with Bu3SnH led to the quantitative formation of (C2F5)2PH. Deprotonation formally yielded the (C2F5)2P– anion in a form that was stabilized by coordination to mercury ions to form the complex [Hg{P(C2F5)2}2(dppe)]. An improved high‐yielding synthesis of (C2F5)2POH was achieved by treating (C2F5)2PNEt2 with p‐toluenesulfonic acid. The gas‐phase structures of (C2F5)2PH and (C2F5)2POH were determined by electron diffraction. The vibrational corrections employed in the data analysis of the diffraction data were derived from molecular dynamics calculations. Both compounds exist in the gas phase mostly as C1‐symmetric cis,cis conformers with regard the orientation of the C2F5 groups relative to the functional groups H and OH. The presence of a second conformer at ambient temperature is likely in both cases. The refined amounts of dominant conformers are 94(6) and 85(6) % for (C2F5)2PH and (C2F5)2POH, respectively. The conformational behaviour was further explored by potential energy surface scans based on DFT calculations. Important experimental structural parameters for the most stable conformers are re(P–C)average = 1.884(3) Å for (C2F5)2PH and re(P–C)average = 1.894(4) Å and re(P–O) = 1.582(3) Å for (C2F5)2POH. The different coordination properties of (C2F5)3P, (C2F5)2POH, (CF3)3P and (CF3)2POH were evaluated by complex formation with [Ni(CO)4]: the maximum achievable number of CO ligands substituted by (C2F5)3P is 1, by (C2F5)2POH is 2, by (CF3)3P is 3 and by the smallest ligand (CF3)2POH is 4.

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Section: Preparation Of Bis(pentafluoroethyl)phosphane Derivativesmentioning

confidence: 99%

“…[6,9] The C 2 F 5 group can also be introduced by the fluoride-mediated reaction of C 2 F 5 SiMe 3 with (PhO) 2 -PC 2 H 4 P(OPh) 2 . [10] The reaction of white phosphorus with C 2 F 5 I under high pressure and temperatures is not a favourable alternative to the synthesis of bis(pentafluoroethyl)phosphane derivatives.…”

Section: Introductionmentioning

confidence: 99%

Functionalized Bis(pentafluoroethyl)phosphanes: Improved Syntheses and Molecular Structures in the Gas Phase

et al. 2013

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“…Taking into account our continuous investigations of cyclic imines reactivity [38][39][40][41][42][43] and having now in hands a-trifluoromethyl-and a-pentafluoroethyl-substituted 3,4-dihydropyrroles and 2,3,4,5-tetrahydropiperidines [42,43], it seems reasonable to apply the similar methodology for the formation of saturated cyclic a-amino-a-perfluoroalkylphosphonates. Although electron-withdrawing properties of fluorinated substituents might inhibit the reactivity of C N double bond, in the case of success such approach would provide easy access to previously unknown fluorinated cyclic aminophosphonates with saturated structure.…”

Section: Resultsmentioning

confidence: 99%

“…The starting cyclic imines 5a-d were obtained according to known procedures [42,43]. (R)-binaphthylphosphoric acid was obtained from (R)-BINOL via the literature procedure [47].…”

Section: Generalmentioning

confidence: 99%

Facile synthesis of cyclic α-perfluoroalkyl-α-aminophosphonates

Odinets

Аrtyushin

Shevchenko

et al. 2009

Journal of Fluorine Chemistry

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“…2 Pipecolinic acid (homoproline) is abundant in many drugs and natural products such as immunosuppresants or cyclic peptides with antifungal activity. 3 Recently, the synthesis of a-trifluoromethyl (a-CF 3 ) proline 4 and C 2 F 5 -proline 5 have been described. CF 3 -Imino acids derivatives (with five-, six-, or seven-membered cycle) have been also obtained by ring-closing metathesis.…”

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confidence: 99%

Efficient Multicomponent Synthesis of α-Trifluoromethyl Proline, Homoproline, and Azepan Carboxylic Acid Dipeptides

Gulevich¹,

Shevchenko²,

Баленкова³

et al. 2009

Synlett

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New method of preparation of C2F5Li and its reactions with cyclic imines and lactims: Synthesis of α-pentafluoroethyl proline

Cited by 58 publications

References 41 publications

Functionalized Bis(pentafluoroethyl)phosphanes: Improved Syntheses and Molecular Structures in the Gas Phase

Functionalized Bis(pentafluoroethyl)phosphanes: Improved Syntheses and Molecular Structures in the Gas Phase

Facile synthesis of cyclic α-perfluoroalkyl-α-aminophosphonates

Efficient Multicomponent Synthesis of α-Trifluoromethyl Proline, Homoproline, and Azepan Carboxylic Acid Dipeptides

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