- Methyl to trifluoromethyl substitution as a strategy to increase the membrane permeability of short peptides
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Here, we investigated the effect of CH3to CF3substitution on the membrane permeability of peptides. We synthesized a series of peptides with CF3groups and corresponding nonfluorinated peptides and measured the membrane per
- Aikawa, Kohsuke,Morimoto, Jumpei,Okazoe, Takashi,Ono, Takahiro,Sando, Shinsuke
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supporting information
p. 9386 - 9389
(2021/11/17)
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- POLYCYCLIC TLR7/8 ANTAGONISTS AND USE THEREOF IN THE TREATMENT OF IMMUNE DISORDERS
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The present invention relates to compounds of Formula (I) and pharmaceutically acceptable compositions thereof, useful as toll-like receptor 7/8 (TLR7/8) antagonists. In Formula (I), Ring A is aryl or heteroaryl; Ring B is aryl or heteroary; and X is C(R4)2, O, NR4, S, S(R4), or S(R4)2.
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Paragraph 00588
(2017/07/06)
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- Preparation of fluoroalkyl imines, amines, enamines, ketones, α-amino carbonyls, and α-amino acids from primary enamine phosphonates
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A simple method for preparation of fluoroalkyl β-enaminophosphonates 1 from alkylphosphonates 2 and perfluoroalkyl nitriles 3 is reported. Olefination reaction of functionalized phosphates 1 with aldehydes gives α,β-unsaturated imines 5. Acid hydrolysis of these fluoroalkyl derivatives 5 affords α,β-unsaturated ketones 6, while their selective reduction with hydrides leads to the formation of allylamines 7, enamines 8, and saturated ketones 9 or amines 10. Selective oxidative cleavage of the carbon-carbon double bond of allylamines 7 gives fluorinated α-amino aldehydes 12, α-amino ketones 13, or α-amino acid derivatives 14.
- Palacios, Francisco,Ochoa De Retana, Ana Maria,Pascual, Sergio,Oyarzabal, Julen
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p. 8767 - 8774
(2007/10/03)
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- The 'non-oxidative' Pummerer reaction: Conclusive evidence for S(N)2- type stereoselectivity, mechanistic insight, and synthesis of enantiopure L- α-trifluoromethylthreoninate and D-α-trifluoromethyl-allo-threoninate
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Enantiopure methyl D-α-trifluoromethyl-allo-threoninate 18 and L-α- trifluoromethylthreoninate 19 were synthesized using (R)-ethyl p- tolylsulfoxide as chiral α-hydroxyethyl anion equivalent. The key step was the S(N)2-type replacement of the sulfinyl auxiliary with a hydroxy group, via trifluoroacetic anhydride promoted 'non-oxidative' Pummerer reaction (NOPR) of the diastereomeric intermediate β-sulfinyl amines 14 and 15, obtained by condensation of (R)-ethyl p-tolylsulfoxide 13 with the N-Cbz imine of methyl trifluoropyruvate 12. The conclusive evidence for S(N)2-type stereoselectivity of the NOPR was achieved by X-ray diffraction of both the starting diastereomer 14 and the p-bromobenzoate 25, obtained from the threoninate 19. NMR monitoring of the NOPR performed on 15 allowed the detection of a transient intermediate, which was identified as the four membered cyclic σ-sulfurane 27. This intermediate spontaneously rearranged (40 min, rt) into the corresponding sulfenamide 17, probably via an intramolecular displacement of the sulfinyl by a trifluoroacetoxy group, with inversion of configuration at the carbon stereocenter. The same process occurred for the diastereomeric β-sulfinyl amine 14, but the sulfenamide 16 was formed at very fast rate, thus precluding NMR detection of the corresponding σ-sulfurane intermediate 26. One-pot treatment of the diastereomeric sulfenamides 16 and 17 with NaBH4 afforded very good yields of the corresponding threoninates 18 and 19.
- Crucianelli, Marcello,Bravo, Pierfrancesco,Arnone, Alberto,Corradi, Eleonora,Meille, Stefano V.,Zanda, Matteo
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p. 2965 - 2971
(2007/10/03)
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