2311-59-3Relevant articles and documents
Generation and trapping of ketenes in flow
Henry, Cyril,Bolien, David,Ibanescu, Bogdan,Bloodworth, Sally,Harrowven, David C.,Zhang, Xunli,Craven, Andy,Sneddon, Helen F.,Whitby, Richard J.
, p. 1491 - 1499 (2015/03/04)
Ketenes were generated by the thermolysis of alkoxyalkynes under flow conditions, and then trapped with amines and alcohols to cleanly give amides and esters. For a 10 min reaction time, temperatures of 180, 160, and 140 °C were required for >95% conversion of EtO, iPrO, and tBuO alkoxyalkynes, respectively. Variation of the temperature and flow rate with inline monitoring of the output by IR spectroscopy allowed the kinetic parameters for the conversion of 1-ethoxy-1-octyne to be easily estimated (Ea = 105.4 kJ/mol). Trapping of the in-situ-generated ketenes by alcohols to give esters required the addition of a tertiary amine catalyst to prevent competitive [2+2] addition of the ketene to the alkoxyalkyne precursor.
Organocatalytic oxidation of aldehydes to mixed anhydrides
Toledo, Hila,Pisarevsky, Evgeni,Abramovich, Adi,Szpilman, Alex M.
, p. 4367 - 4369 (2013/06/05)
TEMPO catalyzes the direct oxidation of aldehydes to mixed anhydrides in the presence of a carboxylic acid. The anhydrides can be converted in situ to esters, secondary, tertiary or Weinreb amides in high yield. Oxidation of the aldehyde directly to 2-propyl esters is also possible using only catalytic amounts of acid. The oxidation reactions are rapid and take place under mild conditions.
Nickel-catalyzed cross-coupling of unactivated alkyl halides and tosylate carrying a functional group with alkyl and phenyl Grignard reagents
Singh, Surya Prakash,Terao, Jun,Kambe, Nobuaki
scheme or table, p. 5644 - 5646 (2011/02/25)
By the use of catalytic amounts of a nickel salt and a 1,3-butadiene, primary and secondary alkyl Grignard reagents undergo cross-coupling with alkyl bromides, iodide, and tosylate carrying a functional group such as amide, ester, and ketone at 0 °C in THF. The present procedure provides a simple, convenient, and practical method for construction of carbon chains in the presence of various functional groups. PhMgBr also gave the corresponding coupling product in a moderate yield.