《Carbene-catalyzed atroposelective synthesis of axially chiral styrenes》 was written by Yan, Jia-Lei; Maiti, Rakesh; Ren, Shi-Chao; Tian, Weiyi; Li, Tingting; Xu, Jun; Mondal, Bivas; Jin, Zhichao; Chi, Yonggui Robin. Synthetic Route of C4H3ClO2S2This research focused onynal sulfinic acid phenol heterocyclic carbene catalyst addition; axially chiral styrene preparation enantioselective click chem. The article conveys some information:
Axially chiral styrenes bearing a chiral axis between a sterically non-congested acyclic alkene and an aryl ring are difficult to prepare due to the low rotational barrier of the axis. Disclosed here is an N-heterocyclic carbene (NHC) catalytic asym. solution to this problem. The reaction involves ynals, sulfinic acids, and phenols as the substrates with an NHC as the catalyst. Key steps involve selective 1,4-addition of sulfinic anion to acetylenic acylazolium intermediate and sequential E-selective protonation to set up the chiral axis. The reaction affords axially chiral styrenes bearing a chiral axis as the product with up to > 99:1 e.r., > 20:1 E/Z selectivity, and excellent yields. The sulfone and carboxylic ester moieties in the styrene products are common moieties in bioactive mols. and asym. catalysis.Thiophene-2-sulfonyl chloride(cas: 16629-19-9Synthetic Route of C4H3ClO2S2) was used in this study.
Thiophene-2-sulfonyl chloride(cas: 16629-19-9) is a member of sulfonyl chlorides. Sulfonyl chlorides are reactive sulfonic acid derivatives similar in properties and reactivity to acid chlorides of carboxylates. The sulfonic acid group, however, is a highly hindered molecule, containing a tetrahedral configuration of substituents. Synthetic Route of C4H3ClO2S2
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics