2,4,4,6-Tetrabromo-2,5-cyclohexadienone (TABCO), N-Bromosuccinimide (NBS) and Bromine as Efficient Catalysts for Dithioacetalization and Oxathioacetalization of Carbonyl Compounds and Transdithioacetalization Reactions
作者:Nasser Iranpoor、Habib Firouzabadi、Hamid Reza Shaterian、M. A. Zolfigol
DOI:10.1080/10426500211712
日期:2002.5.1
6-tetrabromo-2,5-cyclohexadienone (TABCO), N-bromosuccinimide (NBS), and bromine as efficient catalysts for conversion of carbonyl compounds to their cyclic and acyclic dithioacetals and 1,3-oxathiolanes under mild reaction conditions are described. These catalysts are also used for efficient transdithioacetalization of acetals, diacetals, ketals, acylals, enamines, hydrazones, and oximes with high
SBA-15 functionalized sulfonic acid containing a confined hydrophobic and acidic ionic liquid: a highly efficient catalyst for solvent-free thioacetalization of carbonyl compounds at room temperature
作者:Babak Karimi、Majid Vafaeezadeh
DOI:10.1039/c3ra42286k
日期:——
SBA-15 functionalized sulfonic acid containing a confined ionic liquid has been introduced to convert various carbonylcompounds to their corresponding dithioacetals and dithioketals at room temperature and under solvent-free conditions. It was found that coating SBA-15-Pr-SO3H with the hydrophobic and acidic ionic liquid [OMIm]HSO4 at a loading of 0.8 mL g−1 of silica, afforded paths for faster mass transfer
引入了一种含有受限离子液体的SBA-15官能化磺酸的新应用,可在室温和无溶剂条件下将各种羰基化合物转化为其相应的二硫缩醛和二硫缩酮。发现以0.8 mL g -1的二氧化硅负载疏水性和酸性离子液体[OMIm] HSO 4涂覆SBA-15-Pr-SO 3 H ,提供了将原料更快地质量转移到SBA-15-Pr-SO 3 H中的途径。活动站点。同时,由于酸性位点的协同作用机理,它也可能增加布朗斯台德酸的强度。催化剂可以很容易地回收和再利用至少八个反应循环,而其催化活性只有轻微的损失。
Nickel-Catalyzed Synthesis of Silanes from Silyl Ketones
An unprecedented nickel-catalyzed decarbonylative silylation via CO extrusion intramolecular recombination fragment coupling of unstrained and nondirecting group-assisted silylketones is described. The inexpensive and readily available catalyst performs under mild reaction conditions and enables the synthesis of structurally diverse arylsilanes, including heterocyclic and natural product derivatives
An expedient carbon–sulfur bond formation explored through the cellulose sulfonic acid (CSA) catalyzed dithioacetal protection of carbonyl compounds
作者:Kailas R. Kadam
DOI:10.1080/17415993.2020.1775835
日期:2020.9.2
facile carbon–sulfur bond formation was observed through the cellulose sulfonicacid (CSA) catalyzed dithioacetal protection of carbonyl compounds. In a preliminary study, the synthesis and characterization of functionalized bio-polymer, cellulose sulphonic acid (CSA) was achieved and its catalytic knack for dithioacetal protection was studied. It was discovered that CSA is an efficient, environmentally
Enantioselective monoreduction of different 1,2-diaryl-1,2-diketones catalysed by lyophilised whole cells from Pichia glucozyma
作者:Pilar Hoyos、Giacomo Sansottera、María Fernández、Francesco Molinari、José Vicente Sinisterra、Andrés R. Alcántara
DOI:10.1016/j.tet.2008.06.019
日期:2008.8
In this work we have studied the monoreduction of different 1,2-diaryl-ethanediones (benzils, 1) with lyophilised whole cells from Pichia glucozyma CBS 5766, using the diphenyl compound (benzil, 1a) as model substrate, and extended the enantioselective reduction to structurally different symmetric benzils for producing enantiomerically pure or enriched benzoins (α-hydroxyketones 2) in high yields and