20035-08-9Relevant articles and documents
Poly(S-ethylsulfonyl- l -homocysteine): An α-Helical Polypeptide for Chemoselective Disulfide Formation
Muhl, Christian,Sch?fer, Olga,Bauer, Tobias,R?der, Hans-Joachim,Barz, Matthias
, p. 8188 - 8196 (2018)
Homocysteine and cysteine are the only natural occurring amino acids that are capable of disulfide bond formations in peptides and proteins. The chemoselective formation of asymmetric disulfide bonds, however, is chemically challenging and requires an activating group combining stability against hard nucleophiles, e.g., amines, with reactivity toward thiols and soft nucleophiles. In light of these considerations, we introduced the S-alkylsulfonyl cysteines in our previous work. Here, we present the synthesis and ring-opening polymerization of S-ethylsulfonyl-l-homocysteine N-carboxyanhydrides. We demonstrate that the polymerization leads to narrowly distributed polypeptides (D= 1.1-1.3) with no detectable side reactions in a chain length regime from 11 to 165. In contrast to the already reported cysteine derivatives, poly(S-ethylsulfonyl-l-homocysteine)s do not form β-sheets, which reduce solubility and limit the degree of polymerization of poly(S-ethylsulfonyl-l-cysteine)s to 50. Instead, these polymers form α-helices as confirmed by circular dicroism (CD) experiments and infrared spectroscopy (FT-IR). In comparison to the cysteine derivatives, the α-helix formation leads to slightly faster polymerization kinetics (rate constants from 1.44 × 10-5 to 5.29 × 10-5 s-1). In addition, the ability for the chemoselective formation of asymmetric disulfides is preserved as monitored via 1H NMR experiments. Consequently, this new polypeptide overcomes the chain length limitations of poly(S-ethylsulfonyl-l-cysteine)s and thus provides convenient access to reactive poly(S-ethylsulfonyl-l-homocysteine)s for chemoselective disulfide formation.
Visible-Light-Driven Sulfonation of α-Trifluoromethylstyrenes: Access to Densely Functionalized CF3-Substituted Tertiary Alcohol
Chen, Yi-Xuan,Wang, Zhu-Jun,Xiao, Jun-An,Chen, Kai,Xiang, Hao-Yue,Yang, Hua
supporting information, p. 6558 - 6562 (2021/08/23)
Reported herein is a visible-light-induced sulfonation of α-trifluoromethylstyrenes with sodium sulfinates, which provides a series of α-trifluoromethyl-β-sulfonyl tertiary alcohols. This new synthetic protocol is enabled by a charge-transfer complex between oxygen and sulfinates, featuring broad substrate scope and scalability. Excellent functional group compatibility and chemoselectivity render this method suitable for sulfonation of pharmaceutically relevant molecules. In the presence of D2O, deuteriotrifluorinated products were also obtained, further demonstrating the flexibility and synthetic potentials of this strategy.
Direct sulfonylation of BODIPY dyes with sodium sulfinates through oxidative radical hydrogen substitution at the α-position
Lv, Fan,Guo, Xing,Wu, Hao,Li, Heng,Tang, Bing,Yu, Changjiang,Hao, Erhong,Jiao, Lijuan
supporting information, p. 15577 - 15580 (2020/12/30)
An efficient and convenient protocol for the direct sulfonylation of BODIPY dyes with sodium sulfinates via a radical process is described for the first time. This transformation presented wide substrate scope and high regioselectivity, providing a series of α-sulfonylated BODIPYs. Meaningfully, the sulfonyl group, as a good leaving group, allowed the facile introduction of a variety of functionalities on the BODIPY core. Moreover, a 2,4-dinitrobenzenesulfonyl (DBS) group substituted BODIPY showed dramatically quenched fluorescence via the photoinduced electron transfer (PET) pathway, and was demonstrated as a new fluorescent probe for selective biothiol detection. This journal is
