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。
para-Toluenesulfonic Acid Catalyzed Synthesis of Indenes via a Tandem Friedel–Crafts Alkylation/Hydroarylation of Tertiary Propargylic Alcohols with Electron-Rich Arenes
A simple protocol to synthesize indenes efficiently by PTSA catalyzed tandem Friedel–Crafts alkylation/hydroarylation of tertiary propargylic alcohol with electron-rich arenes is described. The desired indenes were obtained regioselectively in good to very good yields under mild reaction conditions. The allene intermediate was isolated to get an insight into the mechanistic pathway of the indene forming
Synthesis of 3-Alkyl- or 3-Allenyl-2-amidobenzofurans via Electrophilic Cyclization of <i>o</i>-Anisole-Substituted Ynamides with Carbocations
作者:Yulong Kong、Kezhi Jiang、Jian Cao、Lingzi Fu、Lian Yu、Guoqiao Lai、Yuming Cui、Ziqiang Hu、Guanhai Wang
DOI:10.1021/ol303474a
日期:2013.1.18
A facile carbocation-induced electrophilic cyclization reaction has been developed for the synthesis of 3-alkyl- or 3-allenyl-2-amidobenzofurans from o-anisole-substituted ynamides and diarylmethanol or 1,1-diarylprop-2-yn-1-ol.
expedient method was demonstrated for the synthesis of 3‐alkenyl‐3‐amino‐2‐oxindoles from readily available propargylic alcohols and isatin imines in the presence of BF3 ⋅ Et2O as a catalyst under open‐air atmosphere. The above reaction was time‐dependent and further extended to the one‐pot synthesis of highly substituted spiro‐indeneindolones via 1,3‐amino group migration/Friedel‐Crafts cyclization. This
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。