2979-48-8Relevant articles and documents
Organosilatranes with thioester-anchored heterocyclic ring assembly: Cu2+ ion binding and fabrication of hybrid silica nanoparticles
Singh, Gurjaspreet,Rani, Sunita,Saroa, Amandeep,Girdhar, Shally,Singh, Jandeep,Arora, Aanchal,Aulakh, Darpandeep,Wriedt, Mario
, p. 65963 - 65974 (2015)
This work presents the design, synthesis, UV-Vis absorption properties and Cu2+ ion binding of the organo-silicon complexes (3a-h) with different coordination abilities that are derived from mercaptopropylsilatrane (MPS) and respective heteroaromatic carboxylic acids (1a-h). The prepared thioester based organosilatranes (ThE-OS) have been meticulously characterized by a series of characterization techniques such as elemental analyses, FT-IR, NMR (1H, 13C), LC-MS, and structure of 3e was unambiguously determined by X-ray single crystal analyses. All the compounds have shown judicious absorption enhancement in the intensity as well as λmax values on binding with Cu2+ ions compared to other surveyed metal ions. In addition, it is for the first time that the hybrid silica nanoparticles (H-SiNPs) bearing a thioester linkage in the silica framework are reported. The synthesis was achieved conveniently by an in situ co-condensation reaction of tetraethyl orthosilicate (TEOS) with the corresponding ThE-OS. The derivatization of silica is confirmed by FT-IR, 13C and 29Si solid state CP-MAS NMR, UV-Vis, TEM, XRD, TGA and EDX techniques. Furthermore, the H-SiNPs have exhibited greater affinity towards Cu2+ ions than the parent ThE-OS.
Practical Chemoselective Acylation: Organocatalytic Chemodivergent Esterification and Amidation of Amino Alcohols with N-Carbonylimidazoles
Nelson, Hope,Richard, William,Brown, Hailee,Medlin, Abigail,Light, Christina,Heller, Stephen T.
supporting information, p. 22818 - 22825 (2021/09/13)
Chemoselective transformations are a cornerstone of efficient organic synthesis; however, achieving this goal for even simple transformations, such as acylation reactions, is often a challenge. We report that N-carbonylimidazoles enable catalytic chemodivergent aniline or alcohol acylation in the presence of pyridinium ions or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), respectively. Both acylation reactions display high and broad chemoselectivity for the target group. Unprecedented levels of chemoselectivity were observed in the DBU-catalyzed esterification: A single esterification product was obtained from a molecule containing primary aniline, alcohol, phenol, secondary amide, and N?H indole groups. These acylation reactions are highly practical as they involve only readily available, inexpensive, and relatively safe reagents; can be performed on a multigram scale; and can be used on carboxylic acids directly by in situ formation of the acylimidazole electrophile.
Efficient Synthesis of α-Ketothioamides From α-Nitroketones, Amines or DMF and Elemental Sulfur Under Oxidant-Free Conditions
Zhang, Zhenlei,Yang, Jiusi,Yu, Renjie,Wu, Kairui,Bu, Jiping,Li, Shaoke,Qian, Peng,Sheng, Liangquan
supporting information, p. 5209 - 5212 (2021/10/19)
We have developed a practical, general protocol for denitration of readily available α-nitroketones with sulfur and amines to access a broad range of α-ketothioamides under mild conditions. Such a reaction proceeds under metal-, oxidant-, and catalyst-free conditions to provide synthetically useful α-ketothioamides. Furthermore, the mild reaction conditions tolerate a wide range of substrates especially for the synthesis of aliphatic α-ketothioamides which are rarely reported.
Chemoselective acylation of 2-amino-8-quinolinol in the generation of C2-amides or C8-esters
Park, Yongseok,Fei, Xiang,Yuan, Yue,Lee, Sanha,Hur, Joonseong,Park, Sung Jean,Jung, Jae-Kyung,Seo, Seung-Yong
, p. 41955 - 41961 (2017/09/12)
Two different ways to carry out the chemoselective acylation of 2-amino-8-quinolinol with unique features to generate C2-amides or C8-esters were developed. The coupling reaction with a variety of carboxylic acids using EDCI and DMAP provided C8-ester derivatives, whereas N-heteroaromatic acids were not introduced on the C8-hydroxy group, but rather on the C2-amino group under the same conditions. To obtain C2-amides selectively, the anionic nucleophile from 2-amino-8-quinolinol was treated with less reactive acyl imidazolides or esters.
