Halogen shuffling in pyridines: Site selective electrophilic substitutions of 2-chloro-6-(trifluoromethyl)pyridine

Access to C(sp3) borylated and silylated cyclic molecules: hydrogenation of corresponding arenes and heteroarenes

This paper presents a simple and cost-effective hydrogenation method for synthesizing a myriad of cycloalkanes and saturated heterocycles bearing boryl or silyl substituents. The catalyst used are heterogeneous, readily available, bench stable, and recyclable. Also demonstrated is the application of the method to compounds that possess both boryl and silyl groups. When combined with Ir-catalyzed sp2 C-H borylation, such hydrogenations offer a two-step complementary alternative to direct sp3 C-H borylations that can suffer selectivity and reactivity issues. Of practical value to the community, complete stereochemical analyses of reported borylated compounds that were never fully characterized are reported herein.

Regioselective carbon-carbon bond formation of 5,5,5-trifluoro-1-phenylpent-3-en-1-yne

The regioselective carbon–carbon bond formation was studied using 5,5,5-trifluoro-1-phenylpent-3-en-1-yne as a model substrate, and predominant acceptance of electrophiles β to a CF₃ group as well as a deuterium trap experiment of the lithiated species led to the conclusion that the obtained regioselectivity is kinetically determined for the reactions with electrophiles, under equilibration of the possible two anionic species.

Microwave-Assisted Flexible Synthesis of 7-Azaindoles

7-Azaindoles are versatile building blocks, especially in medicinal chemistry, where they serve as bioisosteres of indoles or purines. Herein, we are presenting a robust and flexible synthesis of 1,3- and 1,3,6-substituted 7-azaindoles starting from nicotinic acid derivatives or 2,6-dichloropyridine, respectively. Microwave heating dramatically accelerates the penultimate reaction step, an epoxide-opening-cyclization-dehydration sequence. The functional group compatibility of the reaction is examined as well as the application of the products in further functionalizations.