Oxidative generation of synthetically important amidyl radicals from N-H amides is an appealing and yet challenging task. Previous methods require a stoichiometric amount of a strong oxidant and/or a costly noble-metal catalyst. We report herein the first electrocatalytic method that employs ferrocene (Fc), a cheap organometallic reagent, as the redox catalyst to produce amidyl radicals from N-aryl amides. Based on this radical-generating method, an efficient intramolecular olefin hydroamidation reaction has been developed.
The generation of α-imino gold carbenes via gold-catalyzed intermolecular reaction of azides and ynamides is disclosed. This new methodology allows for highly regioselective access to valuable 2-aminoindoles and 3-amino-β-carbolines in generally good to excellent yields. A mechanistic rationale for this tandem reaction, especially for the observed high regioselectivity, is supported by DFT calculations.
The folding mode
of substrate FPP in sesquiterpene cyclases/synthases
is key to the chemo- and stereoselectivity of the ultimate sesquiterpene
products. However, the precise substrate folding modes in most sesquiterpene
cyclases are still elusive, and it is challenging for theoretical
simulations due to the high flexibility of FPP. Herein, by DFT/MM
MD simulations, we obtain the optimal folding mode of FPP in the 1,6-closure
trichodiene synthase and illuminate the whole catalytic mechanism
for the biosynthesis of trichodiene. Furthermore, a simple and practical
rule is proposed to decipher the relationship between the diverse
FPP folding modes and chemical selectivity toward 1,6- and 1,10-ring
closure, which are common pathways in all sesquiterpene cyclases.
An efficient zinc(II)-catalyzed alkyne oxidation/C-H functionalization sequence was developed, thus leading to highly site-selective synthesis of a variety of isoquinolones and β-carbolines. Importantly, in contrast to the well-established gold-catalyzed intermolecular alkyne oxidation, over-oxidation can be completely suppressed in this system and the reaction most likely proceeds by a Friedel-Crafts-type pathway. Mechanistic studies and theoretical calculations are described.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.