Abstract Indoles, dihydroisoquinolines, and dihydroquinolines were efficiently prepared by ruthenium-catalyzed heterocyclizations of aromatic homo- and bis-homopropargyl amines/amides in the presence of an amine/ammonium base-acid pair. These regioselective 5-endo and 6-endo cyclizations most probably occur by nucleophilic trapping of key ruthenium-vinylidene intermediates. Indoles, dihydroisoquinolines
Copper-Catalyzed Trifluoromethylation/Cyclization of Alkynes for Synthesis of Dioxodibenzothiazepines
作者:Zi-Qi Zhang、Yi-Hao Xu、Jing-Cheng Dai、Yan Li、Jie Sheng、Xi-Sheng Wang
DOI:10.1021/acs.orglett.1c00344
日期:2021.3.19
A facile and efficient approach for the synthesis of the CF3-containing dioxodibenzothiazepines has been developed via copper-catalyzed trifluoromethylation/cyclization of alkynes utilizing a radical relay strategy. This method has demonstrated low catalyst loading, high regiocontrol, and broad scope under mild conditions. Good compatibility for the N-protecting group, gram-scale experiment, and further
A simple and mild photoredox catalytic approach to access difluoroalkylated dioxodibenzothiazepines in high regioselectivity via radical cascadecyclization has been described herein. In contrast to previous methods, this strategy does not involve the use of transition-metal catalysts and avoids the potential disadvantages of inevitable toxicity and the tedious removal process of metal catalysts. The
Ruthenium-Catalyzed Cycloisomerization of Aromatic Homo- and Bis-Homopropargylic Amines/Amides: Formation of Indoles, Dihydroisoquinolines and Dihydroquinolines
作者:Alejandro Varela-Fernández、Jesús A. Varela、Carlos Saá
DOI:10.1002/adsc.201100095
日期:2011.8
Ruthenium-catalyzed cycloisomerizations of aromatic homo- and bis-homopropargylic amines/amides efficiently afford indoles, dihydroisoquinolines and dihydroquinolines. These processes were regioselective (5- and 6-endo cyclizations) on using key Ru vinylidene intermediates. The presence of an amine/ammonium base-acid pair increased the rate of cyclization and facilitated the catalytic turnover.
Oxidative Approach Enables Efficient Access to Cyclic Azobenzenes
作者:Martin S. Maier、Katharina Hüll、Martin Reynders、Bryan S. Matsuura、Philipp Leippe、Tongil Ko、Lukas Schäffer、Dirk Trauner
DOI:10.1021/jacs.9b08794
日期:2019.10.30
high-yielding protocol that relies on the oxidative cyclization of diani-lines. In combination with a modular substrate synthesis, it allows for rapid access to diversely functionalized diazocines on gram scales. Our work systematically explores substituent effects on the photoisomerization and thermal relaxation of diazocines. It will enable their incorporation into a wide variety of functional molecules