41795-36-2Relevant academic research and scientific papers
Hydride affinities of cumulated, isolated, and conjugated dienes in acetonitrile
Zhu, Xiao-Qing,Liang, Hao,Zhu, Yan,Cheng, Jin-Pei
experimental part, p. 8403 - 8410 (2009/04/11)
(Chemical Equation Presented) The hydride affinities (defined as the enthalpy changes in this work) of 15 polarized dienes [five phenyl sulfone substituted allenes (1a), the corresponding five isolated dienes (1b), and the corresponding five conjugated dienes (1c)] in acetonitrile solution were determined by titration calorimetry for the first time. The results display that the hydride affinity scales of the 15 dienes in acetonitrile range from -71.6 to -73.9 kcal/mol for 1a, from -46.2 to -49.7 kcal/mol for 1b, and from -45.0 to -46.5 kcal/mol for 1c, which indicates that the hydride-obtaining abilities of the cumulated dienes (1a) are not only much larger than those of the corresponding conjugated dienes (1c) but also much larger than those of the corresponding isolated dienes (1b). The hydrogen affinities of the 15 dienes as well as the hydrogen affinities and the proton affinities of the radical anions of the dienes (1-.) in acetonitrile were also evaluated by using relative thermodynamic cycles according to Hess's law. The results show that (i) the hydrogen affinities of the neutral dienes 1 cover a range from -44.5 to -45.6 kcal/mol for 1a, from -20.4 to -21.4 kcal/ mol for 1b, and from -17.3 to -18.5 kcal/mol for 1c; (ii) the hydrogen affinities of the radical anions of the dienes (1-.) in acetonitrile cover a range from -40.6 to -47.2 kcal/mol for 1a-., from -21.6 to -29.6 kcal/mol for 1b-., and from -10.0 to -15.4 kcal/mol for 1c-.; (iii) the proton affinities of the 15 1a-. in acetonitrile cover a range from -97.0 to -100.6 kcal/mol for 1a-., from -77.8 to -83.4 kcal/ mol for 1b -., and from -66.2 to -68.9 kcal/mol for 1c-.. The main reasons for the great difference between the cumulated dienes and the corresponding isolated and conjugated dienes in the hydride affinity, hydrogen affinity, and proton affinity have been examined. It is evident that these experimental results should be quite valuable to facilitate the elucidation of the origins of the especially high chemical potencies of the allenes, the choice of suitable hydride reducing agents to reduce the dienes, and the analyses on the reduction mechanisms.
One-pot synthesis of aryl sulfones from alcohols
Murakami, Teiichi,Furusawa, Kiyotaka
, p. 479 - 482 (2007/10/03)
A one-pot synthesis of aryl sulfones from primary alcohols is described. Alcohols were treated with N-bromosuccinimide and triphenylphosphine, followed by addition of sodium arenesulfinate with a catalytic amount of tetrabutylammonium iodide to afford the aryl sulfones in good to high yields.
Tetra-n-butylammonium Oxone. Oxidations under Anhydrous Conditions
Trost, Barry M.,Braslau, Rebecca
, p. 532 - 537 (2007/10/02)
Tetra-n-butylammonium Oxone, readily prepared as a white solid from commercially available Oxone, performs oxidations in anhydrous methylene chloride.Under these conditions, sulfides are oxidized to sulfones in the presence of amines, ketones, esters, car
