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High oxidation‐state carbonyl coupling partners including esters and lactones were reacted with enones to give aldol‐type products directly using two‐fold organoborane catalysis. This new retrosynthetic disconnection to aldol‐type products is compatible with enolisable coupling partners, without self‐condensation, and couples the high reactivity of secondary dialkylboranes with the stability of pinacolboronic esters. Excellent chemoselectivity, substrate scope (including those containing reducible functionalities and free alcohols) and diastereocontrol were achieved to access both the syn‐ and anti‐aldol‐type products. Mechanistic studies confirmed the two‐fold catalytic role of the single secondary borane catalyst for boron enolate formation and formation of an aldehyde surrogate from the ester or lactone coupling partner. [ABSTRACT FROM AUTHOR]

The oxidative dehydrogenation of N‐heterocyclic compounds by using H2O2 as oxidant in combination with polar solvents such as 1,1,1,3,3,3‐hexafluoroisopropanol (HFIP) and H2O is described. Among these two solvents, the best yields for the heteroaromatic compounds were generally achieved in HFIP. However, it is remarkable, that the use of a non toxic solvent such as H2O gave such good yields. Furthermore, the procedure was implemented in larger‐scale and HFIP was distilled from the reaction mixture and reused (up to 5 cycles) without a significant detriment in the reaction outcome. [ABSTRACT FROM AUTHOR]

The oxidative cleavage of indoles (Witkop oxidation) involving the use of H2O2 or urea hydrogen peroxide in combination with a polar solvent has been described. Among these solvents, 1,1,1,3,3,3‐hexafluoroisopropanol (HFIP) stands out as the one affording the corresponding 2‐ketoacetanilides generally in higher yields The protocol described has also enabled the oxidation of different pyrroles and furans derivatives. Furthermore, the procedure was implemented in a larger‐scale and HFIP was distilled from the reaction mixture and reused (up to 4 cycles) without a significant detriment in the reaction outcome, which remarks its sustainability and applicability. [ABSTRACT FROM AUTHOR]