δ-Carbolines and their ring-opened analogs: Synthesis and evaluation against fungal and bacterial opportunistic pathogens
摘要:
Previous studies have indicated that the delta-carboline (2) ring system derived from the natural product cryptolepine (1) may represent a pharmacophore for anti-infective activity. This paper describes the design and synthesis of a small library of substituted delta-carbolines and the evaluation of the anti-fungal and anti-bacterial activities. An evaluation of the anti-bacterial activity of a previously reported library of ring-opened analogs was also conducted to provide an opportunity to test the hypothesis that both group of compounds may have the same biological target. Results indicate that against a selected group of fungal pathogens, substituted delta-carbolinium analogs displayed higher potency and several fold lower cytotoxicity than cryptolepine the parent natural product. Both the delta-carbolinium compounds and their ring-opened analogs, exhibited equally high anti-bacterial activity against the selected pathogens and especially against the gram positive bacteria evaluated. Published by Elsevier Masson SAS.
Chan–Evans–Lam Amination of Boronic Acid Pinacol (BPin) Esters: Overcoming the Aryl Amine Problem
作者:Julien C. Vantourout、Robert P. Law、Albert Isidro-Llobet、Stephen J. Atkinson、Allan J. B. Watson
DOI:10.1021/acs.joc.6b00466
日期:2016.5.6
The Chan–Evans–Lam reaction is a valuable C–N bond forming process. However, aryl boronic acidpinacol (BPin) ester reagents can be difficult coupling partners that often deliver low yields, in particular in reactions with aryl amines. Herein, we report effective reaction conditions for the Chan–Evans–Lam amination of aryl BPin with alkyl and aryl amines. A mixed MeCN/EtOH solvent system was found
作者:Kei Kitamura、Naoyuki Shimada、Craig Stewart、Abdurrahman C. Atesin、Tülay A. Ateşin、Marcus A. Tius
DOI:10.1002/anie.201500881
日期:2015.5.18
A Pd0‐catalyzed asymmetric Nazarov‐type cyclization is described. The optimized ligand for the reaction incorporates a weakly coordinating pyridine ring into a TADDOL‐derived phosphoramidite (TADDOL=α,α,α,α‐tetraaryl‐1,3‐dioxolane‐4,5‐dimethanol). The reaction leads to the formation of cyclopentenones as single diastereoisomers that incorporate two contiguous asymmetric centers, one tertiary and one
B(C<sub>6</sub>
F<sub>5</sub>
)<sub>3</sub>
-Catalyzed Cascade Reduction of Pyridines
作者:Zhi-Yun Liu、Zhi-Hui Wen、Xiao-Chen Wang
DOI:10.1002/anie.201702304
日期:2017.5.15
development hinges upon the realization of a cascade process of dearomative hydrosilylation (or hydroboration) and transfer hydrogenation. The broad functional‐group tolerance (e.g. ketone, ester, unactivated olefins, nitro, nitrile, heterocycles, etc.) implies high practical utility.
已发现B(C 6 F 5)3是一种有效的催化剂,可以用氢化硅烷(或氢硼烷)和胺作为还原剂还原吡啶和其他电子不足的N-杂芳烃。该开发的成功取决于脱芳香氢化硅烷化(或硼氢化)和转移氢化的级联过程的实现。宽泛的官能团耐受性(例如酮,酯,未活化的烯烃,硝基,腈,杂环等)暗示着很高的实用性。
Expedited Palladium-Catalyzed Amination of Aryl Nonaflates through the Use of Microwave-Irradiation and Soluble Organic Amine Bases
作者:Rachel E. Tundel、Kevin W. Anderson、Stephen L. Buchwald
DOI:10.1021/jo052131u
日期:2006.1.1
Microwave-assisted, palladium-catalyzed C−N bond-forming reactions with aryl/heteroaryl nonaflates and aminesusing the soluble aminebases DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or MTBD (7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene) and ligands (1−3) resulted in good to excellent yields (71−99%) of arylamines in short reaction times (1−45 min).