A simple and convenient protocol for the synthesis of benzo-[c]chromen-6-ones and 3-substituted isocoumarins through a Cu I -catalyzed tandem reaction of 2-bromobenzoates with cyclohexane-1,3-diones or acyclic 1,3-diones is developed.Scheme 1. Unexpected formation of 3a from 1 and 2a.[a]673 This strategy can also be extended to the one-pot synthesis of isoquinolin-1(2H)-one and 3,4-dihydrophenanthridine-1,6(2H,5H)-dione.

In this paper, a catalyst-free synthesis of diversely substituted 6H-benzo[c]chromenes and 6H-benzo[c]chromen-8-ols via cascade reactions of 2-(2-(allyloxy)phenyl)furan and 2-(2-( prop-2-ynyloxy)phenyl)furan, featured with intramolecular Diels-Alder reactions of furan with unactivated alkene/alkyne in aqueous media under MWI, was developed. In addition, an environmentally friendly oxidation of 6Hbenzo[c]chromenes into the corresponding benzo[c]chromen-6-ones using aqueous H 2 O 2 as an oxidant, in the absence of any activator/catalyst, was also revealed. † Electronic supplementary information (ESI) available. See

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Buy one get one free: Concurrent introduction of both iodo‐ and carbonyl groups, along with the construction of the benzenoid core, has been achieved through an iodine‐initiated domino reaction of hepta‐1,2‐dien‐6‐yn‐4‐ols. Moreover, cyclization of hepta‐1,2,6‐trien‐4‐ols turns out to also be an efficient pathway toward diversely substituted benzenes.

An environmentally and economically sustainable synthesis of 2‐benzoxazyl ketones and 2‐benzothiazyl ketones through FeCl3·6H2O catalyzed tandem reactions of alkynyl bromides with 2‐amino(thio)phenols in [bmim]BF4 has been developed. Remarkable advantages of this new synthetic strategy include high efficiency, readily available starting materials, and recyclable catalyst and reaction medium.