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A new and effective palladium catalyst supported on a magnesium organosilicate for application in the Heck reaction is presented. A group of compounds comprising 22 examples were synthesized in moderate to high yields (up to 99%) within a short time. The palladium supported on magnesium organosilicate catalyst was characterized as an amorphous solid by SEM, containing around 33% of palladium inside the solid, and even with this low quantity of palladium, the catalyst was very efficient in the Heck reaction. Besides, based on the Scherrer equation, the crystallite size of the synthesized palladium nanoparticles was ultrasmall (around 1.3 nm). This strategy is a simple and efficient route for the formation of C–C bonds via the Heck cross-coupling reaction. [ABSTRACT FROM AUTHOR]

The palladium-catalyzed Suzuki–Miyaura cross-coupling reaction is one of the most important and efficient reactions to prepare a variety of organic compounds, including biaryls. Despite the overwhelming number of reports related to this topic, some methodological difficulties persist in terms of catalyst handling, recovery, and reuse, as well as the reaction media. This work reports the rational design of new, efficient, cost-effective, and reusable palladium catalysts supported on synthetic talc for the Suzuki–Miyaura reaction. From the results, key points were identified: both designed catalysts accelerated the reaction in EtOH and an open-flask setup, affording moderate to excellent yields within a short time (e.g., 30 min) even for deactivated aryl halides; the protocol can be applied to a great number of both cross-coupling partners, showing an excellent functional group tolerance; the catalysts can be recovered and reused without significant loss of activity. This protocol was used for the synthesis of a precursor of angiotensin II inhibitors such as valsartan, losartan, irbesartan, and telmisartan. [ABSTRACT FROM AUTHOR]

Functionalization of 2,1,3‐benzothiadiazole (BTD) with thiols at C‐5 position remains low explored. Moreover, the arylthiol‐substitutions at this position are also unexplored and can not be found by a SN2 or SN1 reaction. In this sense, herein we present a new palladium‐catalyzed methodology for a wide variety of unpublished 5‐arylsulfanyl‐benzo‐2,1,3‐thiadiazole derivatives synthesis with moderate to high yields using a low catalytic loading of Pd(L‐Pro)2 as low‐coast, and efficient catalyst in low reaction time. Besides, we concluded that the pKa of thiol species has an important role in this catalysis, mainly in the CMD like catalytic cyclo process, which strongly interferes in the reaction yields. Furthermore, arylsulfanyl‐benzo‐2,1,3‐thiadiazoles derivatives have been assessed (in vitro) as potential acetylcholinesterase inhibitors. [ABSTRACT FROM AUTHOR]