A Rh(III)-catalyzed direct selenium annulation by using stable and tractable elemental selenium is developed. A series of benzamides as well as acrylamides were successfully coupled with selenium under mild reaction conditions to give isoselenazolone derivatives. An unprecedented selenation mechanism involving an electrophilic Se(IV) species as the reactive selenium donor is proposed based on the designed
Direct Enantioselective C(sp<sup>3</sup>)–H Acylation for the Synthesis of α-Amino Ketones
作者:Xiaomin Shu、Leitao Huan、Qian Huang、Haohua Huo
DOI:10.1021/jacs.0c10471
日期:2020.11.11
under mild conditions. The synthetic utility of this method is further demonstrated by gram scale synthesis and application to late-stage functionalization. This method provides an unprecedented solution to address the challenging stereocontrol in metallaphotoredox catalysis and C(sp3)-H functionalization. Mechanistic studies suggest the α-C(sp3)-H bond of the benzamide coupling partner is cleavage
Generation of Functionalized Alkyl Radicals via the Direct Photoexcitation of 2,2′-(Pyridine-2,6-diyl)diphenol-Based Borates
作者:Yusuke Miyamoto、Yuto Sumida、Hirohisa Ohmiya
DOI:10.1021/acs.orglett.1c01996
日期:2021.8.6
was developed for the purpose of generating radicals via direct photoexcitation. These borates were prepared using 2,2′-(pyridine-2,6-diyl)diphenol as a tridentate ligand together with organoboronic acids or potassium trifluoroborates. The ready availability of organoboroncompounds is a significant advantage of this direct photoexcitation protocol. The excited states of these borates can also serve
Incorporation of the CF3 group into arenes has found increasing importance in drug discovery. Herein, we report the first photoredox-catalyzed cross-coupling of aryl thianthrenium salts with a copper-based trifluoromethyl reagent, which enables a site-selective late-stagetrifluoromethylation of arenes. The reaction proceeds with broad functional group tolerance, even for complex small molecules on
Selective C(sp3)–H isothiocyanation represents a significant strategy for the synthesis of isothiocyanate derivatives. We report herein an electrochemicalbenzylic isothiocyanation in a highly chemo- and site-selective manner under external oxidant-free conditions. The high chemoselectivity is attributed to the facile in situ isomerization of benzylic thiocyanates to isothiocyanates. Notably, the method