114533-13-0Relevant academic research and scientific papers
Transamidation of primary amides with amines catalyzed by zirconocene dichloride
Atkinson, Benjamin N.,Chhatwal, A. Rosie,Lomax, Helen V.,Walton, James W.,Williams, Jonathan M. J.
supporting information, p. 11626 - 11628,3 (2012/12/12)
Zirconocene dichloride (Cp2ZrCl2) has been shown to be an effective catalyst for the transamidation of primary amides with amines in cyclohexane at 80°C in 5-24 hours. For favourable substrates, the reaction can be performed at temperatures as low as 30°C.
Transamidation of primary amides with amines catalyzed by zirconocene dichloride
Atkinson, Benjamin N.,Chhatwal, A. Rosie,Lomax, Helen V.,Walton, James W.,Williams, Jonathan M. J.
supporting information, p. 11626 - 11628 (2013/01/15)
Zirconocene dichloride (Cp2ZrCl2) has been shown to be an effective catalyst for the transamidation of primary amides with amines in cyclohexane at 80°C in 5-24 hours. For favourable substrates, the reaction can be performed at temperatures as low as 30°C.
Photosensitized oxidation of alkyl phenyl sulfoxides. C-S bond cleavage in alkyl phenyl sulfoxide radical cations
Baciocchi, Enrico,Del Giacco, Tiziana,Lanzalunga, Osvaldo,Mencarelli, Paolo,Procacci, Barbara
, p. 5675 - 5682 (2008/12/22)
(Chemical Equation Presented) The 3-cyano-N-methylquinolinium Perchlorate (3-CN-NMQ+ ClO4-)-photosensitized oxidation of phenyl alkyl sulfoxides (PhSOCR1R2R3,1, R1 = R2 = H, R3 = Ph; 2, R1 = H, R2 = Me, R3 = Ph; 3, R1 = R2 = Ph, R3 = H; 4, R1 = R2 = Me, R3 = Ph; 5, R1 = R2 = R3 = Me) has been investigated by steady-state irradiation and nanosecond laser flash photolysis (LFP) under nitrogen in MeCN. Steady-state photolysis showed the formation of products deriving from the heterolytic C-S bond cleavage in the sulfoxide radical cations (alcohols, R 1R2R3COH, and acetamides, R1R 2R3CNHCOCH3) accompanied by sulfur-containing products (phenyl benzenethiosulfinate, diphenyl disulfide, and phenyl benzenethiosulfonate). By laser irradiation, the formation of 3-CN-NMQ ? (λmax = 390 nm) and sulfoxide radical cations 1?+, 2?+, and 5?+ (λmax = 550 nm) was observed within the laser pulse. The radical cations decayed by first-order kinetics with a process attributable to the heterolytic C-S bond cleavage leading to the sulfinyl radical and an alkyl carbocation. The radical cations 3?+ and 4?+ fragment too rapidly, decaying within the laser pulse. The absorption band of the cation Ph2CH+ (λmax = 440 nm) was observed with 3 while the absorption bands of 3-CN-NMQ? and PhSO? (λmax = 460 nm) were observed just after the laser pulse in the LFP experiment with 4. No competitive β-C-H bond cleavage has been observed in the radical cations from 1-3. The C-S bond cleavage rates were measured for 1?+, 2?+, and 5?+. For 3?+ and 4?+, only a lower limit (ca. >3 × 107 s-1) could be given. Quantum yields (Φ) and fragmentation first-order rate constants (k) appear to depend on the structure of the alkyl group and on the bond dissociation free energy (BDFE) of the C-S bond of the radical cations determined by a thermochemical cycle using the C-S BDEs for the neutral sulfoxides 1-5 obtained by DFT calculations. Namely, Φ and k increase as the C-S BDFE becomes more negative, that is in the order 1 ?+ (1.4 × 106 s-1) with the upper limit (104 s-1) given for fert-butyl phenyl sulfide radical cation (Baciocchi, E.; Del Giacco, T.; Gerini, M. F.; Lanzalunga, O. Org. Lett. 2006, 8, 641-644). It turns out that sulfoxide radical cations undergo C-S bond breaking at a rate at least 2 orders of magnitude faster than that of corresponding sulfide radical cations.
Expedient synthesis of deuterium-labelled amides within micro-reactors
Hooper, Julian,Watts, Paul
, p. 189 - 196 (2008/02/08)
The pharmaceutical industry relies heavily on the synthesis of small quantities (10-500 mg) of stable, isotopically labelled compounds in the evaluation of new drug candidates for metabolism studies. As a result of the phenomenal cost of labelled materials even the preparation of small quantities can be extremely expensive. In this paper, for the first time, we report that micro-reactor technology may be used to prepare stable deuterium-labelled compounds by conducting all optimization experiments using unlabelled precursors and simply substituting the labelled derivatives once the optimization is complete. Here, we wish to present a simple, general procedure for the synthesis of amides containing isotopic labels demonstrated using [C-2H 3]acetyl chloride 1. The reaction is carried out within a micro-reactor set-up which we believe offers superiority over other reported methods viz requiring stoichiometric quantities of reagents, high containment of the system and generality of the technique, obtaining products in high yields. Copyright
