Sulfonium ylide formation and subsequent C S bond cleavage of aromatic isopropyl sulfide catalyzed by hemin in aqueous solvent
作者:Xiaojing Yan、Chang Li、Xiaofei Xu、Quan He、Xiaoyong Zhao、Yuanjiang Pan
DOI:10.1016/j.tet.2019.04.035
日期:2019.6
Heme is an abundant and widely existed cofactor for a variety of metalloenzymes, whose broader use is generally impeded by its high instability and poor solubility. Here we report an environment-benign and efficient strategy for the sulfonium ylide formation and subsequent CS bondcleavage of aromatic isopropyl sulfides, which was catalyzed by hemin in assistance of Triton X-100. This aqueous catalytic
(vinylthio)benzene (1) and then an electrophilic quenching followed by a further metalation/electrophilic quenching is a general method to prepare in one pot (alkylthio)benzenesortho, alpha-substituted with equal or different groups. The direct dimetalation of 1 affords the ortho, alpha-dilithiated species 15 besides other by-products. Starting from 15 it is possible to obtain in one step ortho, alpha-substituted
Base‐Mediated Radical Borylation of Alkyl Sulfones
作者:Mingming Huang、Jiefeng Hu、Ivo Krummenacher、Alexandra Friedrich、Holger Braunschweig、Stephen A. Westcott、Udo Radius、Todd B. Marder
DOI:10.1002/chem.202103866
日期:2022.1.13
The utilization of inactivated alkyl sulfones as alkylradical precursors in a base-mediated borylation reaction with B2neop2 is reported, allowing direct access to valuable alkyl boronate esters without further transesterification. This approach is scalable and is tolerant to a variety of functional groups and substrates including complex molecules.
据报道,在与 B 2 neop 2的碱介导的硼基化反应中,利用失活的烷基砜作为烷基自由基前体,从而无需进一步酯交换即可直接获得有价值的烷基硼酸酯。这种方法具有可扩展性,并且能够耐受各种官能团和底物,包括复杂分子。
Transalkylation of alkyl aryl sulfides with alkylating agents
produces methylphenylsulfide. This transalkylation reaction was further studied by 1H NMR spectroscopy. The polarity of the solvent, the electron density on the sulfur atom, and the strength of the alkylatingagent (MeI, EtI, BuI, dimethyl sulfate, or dimethyl carbonate) played important roles in the reaction. The suggested mechanism of the reaction involves the formation of a dialkyl aryl sulfonium salt
甲基碘与叔丁基苯硫在DMF中的反应导致烷基转移,生成甲基苯硫。通过1 H NMR光谱进一步研究了该烷基转移反应。溶剂的极性,硫原子上的电子密度以及烷基化剂(MeI,EtI,BuI,硫酸二甲酯或碳酸二甲酯)的强度在反应中起着重要作用。所建议的反应机理涉及形成二烷基芳基formation盐,该盐随后消除了该基团。观察到硫原子上具有更多支链烷基的化合物具有更高的转化率,从而支持了该机理,这可能导致形成更稳定的自由基。