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A new and efficient protocol has been demonstrated for the synthesis of benzothiadiazinoisoquinoline 6,6-dioxides and benzothiadiazinoisoindole 5,5-dioxides in good to excellent yields. These compounds are formed through a sequential Rh(III)-catalyzed C-H cyclization of dihydrophenylbenzothiadiazine 1,1-dioxides with alkynes and oxidative Heck coupling/aza-Michael addition of dihydrophenylbenzothiadiazine 1,1-dioxides with acrylates, respectively.

An efficient and convenient method for the synthesis of highly substituted polycyclic pyridinium salts from the reaction of various 2-aryl-pyridines and 2-aryl-sp(2) -nitrogen-atom-containing heterocycles with alkynes through rhodium(III)-catalyzed CH activation and annulation under an O2 atmosphere is described. A possible mechanism that involves the chelation-assisted CH activation of the 2-aryl-pyridine substrate, insertion of the alkyne, and reductive elimination is proposed. This mechanism was supported by the isolation of a five-membered rhodacycle (I'). In addition, kinetic isotope studies were performed to understand the intimate reaction mechanism., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Described herein is a convenient and highly regioselective synthesis of substituted isoquinoline derivatives from various aromatic ketoximes and alkynes via a one-pot, rhodium-catalyzed C-H bond activation. In addition, tetrahydroquinoline derivatives are formed in good yields from 2-arylidene-1-cyclohexanone oximes possessing an exocyclic double bond and from tetrahydroxanthone oximes. A possible mechanism is proposed that involves chelation-assisted C-H activation via oxidative addition of Rh(I) to an ortho-C-H bond, insertion of the alkyne, reductive elimination, intramolecular electrocyclization, and aromatization. This mechanism is supported by isolation of the ortho-alkenylation products 7p and 7q. Also described herein is an example of an iridium-catalyzed activation of an sp(3) C-H bond.

A protocol for the rhodium(III)-catalyzed annulation of N-methoxybenzamides with 7-oxa/azabenzonorbornadienes by C–H activation was developed. This method allowed the synthesis of polycyclic products containing an oxygen/nitrogen-bridged structure in excellent yields. The annulated products were successfully transformed into benzo[b]by a ring-opening/aromatization sequence. [ABSTRACT FROM AUTHOR]

Rhodium-catalyzed directed CH-functionalizations have been used in hydroarylations of heterobicyclic alkenes with NH-sulfoximines. Unexpectedly, the bicyclic framework is retained, resulting in the formation of addition products being attractive intermediates for functionalized molecules that are difficult to prepare by other means. [ABSTRACT FROM AUTHOR]

A new method for the synthesis of highly substituted naphthyridine-based polyheteroaromatic compounds in high yields proceeds through rhodium(III)-catalyzed multiple CH bond cleavage and CC and CN bond formation in a one-pot process. Such highly substituted polyheteroaromatic compounds have attracted much attention because of their unique π-conjugation, which make them suitable materials for organic semiconductors and luminescent materials. Furthermore, a possible mechanism, which involves multiple chelation-assisted ortho CH activation, alkyne insertion, and reductive elimination, is proposed for this transformation. [ABSTRACT FROM AUTHOR]

Two new rhodium-catalyzed oxidative couplings between sulfoximine derivatives and alkenes by regioselective CH activation, affording ortho-olefinated (Heck-type) products, are reported. A synthetic application of the ortho-alkenylated products into the corresponding cyclic derivatives has been demonstrated, and a mechanistic rational for the rhodium catalysis is presented. [ABSTRACT FROM AUTHOR]

Revitalization by oxygen: A rhodium(III)‐catalyzed oxidative CH/NH activation/annulation sequence provided access to a variety of substituted 1,2‐benzothiazine derivatives from readily available NH‐sulfoximines and alkynes (see scheme; Cp*=C5Me5). The oxidation system consisted of molecular oxygen in combination with a catalytic amount of Fe(OAc)2. [ABSTRACT FROM AUTHOR]

An efficient and convenient method for the synthesis of highly substituted polycyclic pyridinium salts from the reaction of various 2-aryl-pyridines and 2-aryl-sp2-nitrogen-atom-containing heterocycles with alkynes through rhodium(III)-catalyzed CH activation and annulation under an O2 atmosphere is described. A possible mechanism that involves the chelation-assisted CH activation of the 2-aryl-pyridine substrate, insertion of the alkyne, and reductive elimination is proposed. This mechanism was supported by the isolation of a five-membered rhodacycle ( I′). In addition, kinetic isotope studies were performed to understand the intimate reaction mechanism. [ABSTRACT FROM AUTHOR]

An efficient method for the of substituted phenanthridinone derivatives from N-methoxybenzamides and aryltriethoxysilanes through rhodium-catalyzed dual and is described. A double-cycle mechanism is proposed to account for this catalytic reaction. In addition, isotope-labeling studies were performed to understand the intimate mechanism of the reaction. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Rhodium(III)-Catalyzed Selective ortho-Olefinations of N-Acyl and N-Aroyl Sulfoximines by C-H Bond Activation" by K. Parthasarathy and others, published in the periodical "Chemistry - A European Journal" in 2014.