We report herein an atom-economical and sustainable approach to access amidinyl radical intermediates through the anodic cleavage of N-H bonds. The resulting nitrogen-centered radicals undergo cyclizations with (hetero)arenes, followed by rearomatization, to afford functionalized tetracyclic benzimidazoles in a highly straightforward and efficient manner. This metal- and reagent-free C-H/N-H cross-coupling reaction exhibits a broad substrate scope and proceeds with high chemoselectivity.

The cobalt-catalyzed alkoxylation of C(sp(2) )H bonds in aromatic and olefinic carboxamides has been developed. The reaction proceeded under mild conditions in the presence of Co(OAc)2 ⋅4H2 O as the catalyst and tolerates a wide range of both alcohols and benzamide substrates, including even olefinic carboxamides. In addition, this reaction is the first example of the direct alkoxylation of alkenes through CH bond activation.

A highly efficient cobalt(II)-catalyzed alkynylation/annulation of terminal alkynes assisted by an N,O-bidentate directing group is described. This protocol is characterized by wide substrate scope utilizing cheap cobalt catalysts, and offers a new approach to 3-methyleneisoindolin-1-one, which can be converted into an oxadiazine salt in one step. Moreover, the directing group could be removed in three steps.

An unprecedented synthesis of N-heteroaromatics from biaryl aldehydes and NH through reagent-free C-H/N-H cross-coupling has been developed. The electrosynthesis uses NH as an inexpensive and atom-economic nitrogen donor, requires no oxidizing agents, and allows efficient and regioselective access to a wide range of phenanthridines and structurally related polycyclic N-heteroaromatic products.

Aldehyde is one of most synthetically versatile functional groups and can participate in numerous chemical transformations. While a variety of simple aromatic aldehydes are commercially available, those with a more complex substitution pattern are often difficult to obtain. Benzylic oxygenation of methylarenes is a highly attractive method for aldehyde synthesis as the starting materials are easy to obtain and handle. However, regioselective oxidation of functionalized methylarenes, especially those that contain heterocyclic moieties, to aromatic aldehydes remains a significant challenge. Here we show an efficient electrochemical method that achieves site-selective electrooxidation of methyl benzoheterocycles to aromatic acetals without using chemical oxidants or transition-metal catalysts. The acetals can be converted to the corresponding aldehydes through hydrolysis in one-pot or in a separate step. The synthetic utility of our method is highlighted by its application to the efficient preparation of the antihypertensive drug telmisartan.

We report herein an atom-economical and sustainable approach to access amidinyl radical intermediates through the anodic cleavage of NÀH bonds. The resulting nitrogencentered radicals undergo cyclizations with (hetero)arenes, followed by rearomatization, to afford functionalized tetracyclic benzimidazoles in a highly straightforward and efficient manner. This metal-and reagent-free C À H/N À H cross-coupling reaction exhibits a broad substrate scope and proceeds with high chemoselectivity. Scheme 1. Formation and cyclization of NCRs. Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under http://dx.These are not the final page numbers! Ü Ü Scheme 4. Gram-scale synthesis.Scheme 5. Extension of the current method. Energies are in kcal mol À1 .Scheme 6. Mechanistic studies.

An unprecedented synthesis of N‐heteroaromatics from biaryl aldehydes and NH3 through reagent‐free C−H/N−H cross‐coupling has been developed. The electrosynthesis uses NH3 as an inexpensive and atom‐economic nitrogen donor, requires no oxidizing agents, and allows efficient and regioselective access to a wide range of phenanthridines and structurally related polycyclic N‐heteroaromatic products.

We report a step-economical, enantioselective total synthesis of (−)-robustanoid B and (−)-robustanoid A and four novel natural product-like compounds. Our strategy relied on our biosynthetic hypothesis and on a novel complexity generation methodology, namely, the one-pot hydroxylative double cyclization reaction. The latter consists of a modified 3,3dimethyldioxirane-triggered epoxidationepoxide-ring-opening cyclization reaction cascade and Trost's regioselectivity umpolung methodology ("anti-Michael addition").