156730-39-1Relevant articles and documents
A Broad-Spectrum Catalytic Amidation of Sulfonyl Fluorides and Fluorosulfates**
Wei, Mingjie,Liang, Dacheng,Cao, Xiaohui,Luo, Wenjun,Ma, Guojian,Liu, Zeyuan,Li, Le
, p. 7397 - 7404 (2021)
A broad-spectrum, catalytic method has been developed for the synthesis of sulfonamides and sulfamates. With the activation by the combination of a catalytic amount of 1-hydroxybenzotriazole (HOBt) and silicon additives, amidations of sulfonyl fluorides and fluorosulfates proceeded smoothly and excellent yields were generally obtained (87–99 %). Noticeably, this protocol is particularly efficient for sterically hindered substrates. Catalyst loading is generally low and only 0.02 mol % of catalyst is required for the multidecagram-scale synthesis of an amantadine derivative. In addition, the potential of this method in medicinal chemistry has been demonstrated by the synthesis of the marketed drug Fedratinib via a key intermediate sulfonyl fluoride 13. Since a large number of amines are commercially available, this route provides a facile entry to access Fedratinib analogues for biological screening.
Studies on s-Cis/s-Trans Preference of Acyclic α,β-Unsaturated Esters. Reactions, Supersonic Jet Spectroscopy, NOEs, and X-ray Analysis
Shida, Naomi,Kabuto, Chizuko,Niwa, Taeko,Ebata, Takayuki,Yamamoto, Yoshinori
, p. 4068 - 4075 (2007/10/02)
The s-cis/s-trans preference of acyclic α,β-unsaturated esters has been studied by their reactions to elucidate the preference in the transition state and by supersonic jet spectroscopy, NOE experiments, and X-ray analysis to clarify the preference in the ground state.It has been widely accepted that enolate-Lewis acid complexes prefer the s-trans conformation not only in the ground state but also in the transition state of the reactions involving those complexes.The conjugate addition of metal amides to uncomplexed enoates proceeds predominantly through the s-cis conformation, and most organocopper conjugate additions in the absence of Lewis acids or related metal salts take place preferentially in the s-cis conformation.It is clarified that the relative population of the s-cis and s-trans conformer of uncomplexed methyl cinnamate is nearly 1:1 in a ssupersonic free jet and in solution at room temperature.X-ray analyses of 23 and 24 indicate the c-cis conformation, suggesting that most enoates adopt the s-cis form in the solid state except for 16-18.
