1058680-96-8Relevant academic research and scientific papers
Semipinacol-type rearrangements of [3-(arylsulfonyl)bicyclo[1.1.0]butan-1-yl]alkanols
Kerner, Michael J.,Wipf, Peter
, p. 3615 - 3619 (2021)
Selective lithiation of arylsulfonylbicyclo[1.1.0]butanes at the bridgehead methine and addition to carbonyl compounds yield tertiary bicyclobutyl alcohols that form spiro[3.4]octanes and related heteroatom-containing spirocycles via an acid- or halogen-mediated semipinacol rearrangement. Further synthetic transformations at the carbonyl or arylsulfone positions, in general in high yield and good chemoselectivity, allow access to acetals, difluorides, amides, and methylenecyclobutene building blocks.
Photochemical Strain-Release-Driven Cyclobutylation of C(sp3)-Centered Radicals
Ernouf, Guillaume,Chirkin, Egor,Rhyman, Lydia,Ramasami, Ponnadurai,Cintrat, Jean-Christophe
supporting information, p. 2618 - 2622 (2019/11/19)
A new photoredox-catalyzed decarboxylative radical addition approach to functionalized cyclobutanes is described. The reaction involves an unprecedented formal Giese-type addition of C(sp3)-centered radicals to highly strained bicyclo[1.1.0]but
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.
