Iodolopyrazolium Salts: Synthesis, Derivatizations, and Applications
作者:Andreas Boelke、Thomas J. Kuczmera、Lucien D. Caspers、Enno Lork、Boris J. Nachtsheim
DOI:10.1021/acs.orglett.0c02593
日期:2020.9.18
The synthesis of iodolopyrazolium triflates via an oxidative cyclization of 3-(2-iodophenyl)-1H-pyrazoles is described. The reaction is characterized by a broad substrate scope, and various applications of these novel cyclic iodolium salts acting as useful synthetic intermediates are demonstrated, in particular in site-selective ring openings. This was finally applied to generate derivatives of the
Copper‐Catalyzed Synthesis of Substituted 4‐Quinolones using Water as a Benign Reaction Media: Application for the Construction of Oxolinic Acid and BQCA
作者:Babasaheb Sopan Gore、Chein Chung Lee、Jessica Lee、Jeh‐Jeng Wang
DOI:10.1002/adsc.201900286
日期:2019.7.11
−NO2, −SO2Ar, and −COAr were also successful. In addition, reaction with heterocyclic compounds such as 3‐(3‐bromothiophen‐2‐yl)‐3‐oxopropanenitrile proceeded smoothly to afford tetrahydrothieno[3,2‐b]pyridine‐6‐carbonitrile analogues. The practicality of the designed protocol was confirmed by gram scale synthesis of two derivatives.
已开发出一种铜催化的三组分合成方法,用于从取代的3-(2-卤代苯基)-3-氧代丙烷,醛和水溶液合成取代的4-喹诺酮衍生物。NH 3使用水作为对环境无害的反应介质。此外,所获得产品的合成效用已成功地用于合成可用的亚氧酸和BQCA药物。该方法的关键特征包括可商购的起始原料,广泛的范围以及中等至良好的反应产率。与甲醛反应,以及其他官能团,例如-CN,-NO 2,-SO 2Ar和-COAr也成功。此外,与杂环化合物(如3-(3-溴噻吩-2-基)-3-氧代丙烷腈)的反应进行得很顺利,得到了四氢噻吩并[3,2 - b ]吡啶-6-腈的类似物。两种衍生物的克级合成证实了所设计方案的实用性。
Iridium Diamine Catalyst for the Asymmetric Transfer Hydrogenation of Ketones
作者:Henar Vázquez-Villa、Stefan Reber、Martin A. Ariger、Erick M. Carreira
DOI:10.1002/anie.201102732
日期:2011.9.12
A simple and very efficient chiral aqua iridium(III) diamine complex leads to excellent enantioselectivities in the asymmetrictransferhydrogenation of various α‐cyano and α‐nitro ketones. The catalyst provides the ortho‐substituted aromatic alcohols with especially high ee values. The diamine ligands can be used directly as chiral ligands; conversion into the corresponding sulfamide is not necessary
Tertiary amine-catalyzed (3+3) annulations of δ-acetoxy allenoates: Substrate scope, synthetic application and mechanistic insight
作者:Chunjie Ni、Weiping Zhou、Xiaofeng Tong
DOI:10.1016/j.tet.2017.04.058
日期:2017.6
highly stereoselective synthesis of the core of calyxin I. Mechanistic experiments suggest the involvement of 3-ammonium-2,4-dienoate intermediate BN. This type of cationic intermediate arises from an addition-elimination process between allenoate substrate and amine catalyst, and is stable enough for isolation and characterization. Mechanistic studies also disclose the crucial role of amide NH of 5g
CsOH·H2O-catalyzed formal [3 + 3] cycloadditions of allenyl imide with β-ketoesters, 1,3-diketones or β-ketonitriles for the synthesis of tetrasubstituted 2-pyrone derivatives have been demonstrated. The allenyl imide was utilized as a C3-synthon, and a ketenyl intermediate was proposed via the process of 1,4-addition of carbon anion to allene followed by elimination of the 2-oxazolidinyl group.