Synthesis of Tetraarylallenes via Palladium-Catalyzed Addition-Elimination Reactions of 1,1,3-Triaryl-2-propyn-1-ols with Aryl Iodides
作者:Ming-Jung Wu、Li-Mei Wei、Li-Lan Wei、Wen-Bin Pan
DOI:10.1055/s-2005-872228
日期:——
The palladium-catalyzed reactions of tert-propargylic alcohols with aryl iodides afforded tetraarylallenes in good yields. This reaction involves: (1) oxidative addition of the aryl iodide to Pd(0); (2) arylpalladium intermediate coordination to the carbon-carbon triple bond of the 1,1,3-triaryl-2-propyn-1-ol and subsequent regioselective insertion of the alkynol to form β-hydroxyvinylpalladium species; and (3) β-elimination to produce the tetraarylallenes. Generally, the best results are obtained by employing 5 mol% of Pd(TFA)2, 10 mol% of PPh3, two equivalents of aryl iodide and five equivalents of Et3N in MeCN.
An unprecedented Lewis acidcatalyzed, protection-free, and high-efficiency synthesis of valuable 3,4-dihydro-2H-2,4-methanochromans via cycloaddition of propargylic alkynols with 2-vinylphenol is described. This cycloaddition protocol, which tolerates a wide variety of functional groups, provides practical, versatile, and atom-economical access to a new class of appealing bridged-ring products in
本文描述了一种空前的路易斯酸,其通过炔丙基炔醇与2-乙烯基苯酚的环加成反应,催化了有价值的3,4-二氢-2 H -2,4-甲烷二甲基苯并没有保护性地进行了高效合成。该环加成方案可耐受多种官能团,以令人满意的收率提供实用,通用且经济实惠的途径来获得新型的有吸引力的桥环产品。与报道的桥环骨架合成反应条件相比,目前的反应条件是中性,温和且没有任何添加剂。
<scp>Transition‐Metal‐Free</scp>
Catalyzed Dehydrative Coupling of Quinoline and Isoquinoline
<scp>
<i>N</i>
‐Oxides
</scp>
with Propargylic Alcohols
short reaction time, operational simplicity, and highly efficient reaction system. This protocol, which produces water as the only byproduct, provides efficient and atom-economical access to a class of fascinating quinoline and isoquinoline products in satisfactory yields. The method is effective on the gram scale, thus highlighting the inherent practicality of this methodology.
介绍了一种新的、绿色的、无过渡金属的方案,用于在Na 2 S 2 O 8存在下,从容易获得且对环境无害的喹啉和异喹啉N-氧化物与炔丙醇开始,用于轻松修饰喹啉和异喹啉衍生物或 K 2 S 2 O 8在 100°C。一锅转化具有官能团相容性好、反应时间短、操作简单、反应体系高效等优点。该协议产生水作为唯一的副产品,提供了以令人满意的收率获得一类引人入胜的喹啉和异喹啉产品的高效和原子经济的途径。该方法在克尺度上是有效的,从而突出了该方法的内在实用性。
Lewis Acid Catalyzed Dehydrogenative Coupling of Tertiary Propargylic Alcohols with Quinoline <i>N</i>-Oxides
An unprecedented Lewisacidcatalyzed, high-efficiency synthesis of valuable 2-(quinolin-2-yl)prop-2-en-1-ones via dehydrogenative coupling of propargylic alkynols with quinoline N-oxides is described. This protocol, which tolerates a broad range of functional groups, provides a straightforward pathway to the products 2-(quinolin-2-yl)prop-2-en-1-one scaffolds in satisfactory yields. The conversion
Acid-catalyzed allenylation of pyrazolones with propargyl alcohols
作者:Wande Zhang、Shiqiang Wei、Jingping Qu、Baomin Wang
DOI:10.1039/d1ob00592h
日期:——
A TsOH-catalyzed allenylation of pyrazolones with propargylic alcohols has been developed. The established reaction system is well tolerated by a wide scope of pyrazolones and propargylic alcohols. The process has the salient features of operational simplicity, facile scale-up and high yield. In particular, the integration of the pharmaceutical-related pyrazolone skeleton and the allenyl group into