We describe the base-mediated [3 + 2] cycloaddition reaction of di/trifluoromethylated hydrazonoyl chlorides with fluoronitroalkenes for the synthesis of densely functionalized 3-di/trifluoroalkyl-5-fluoropyrazoles with potent biological activity.
A variety of pyrazoline-derived N-vinyl nitrones was prepared in moderate to good yields with high regioselectivity and diastereoselectivity through the base-promoted regioselective [3 + 2] cycloaddition of N-vinyl nitrones and hydrazonoyl chlorides.
Aromatic 1,2,4-diazaphospholes featuring distinct hybrid-mode nitrogen atoms (N(λ3σ2), N(λ3σ3)) and low-valent phosphorus atoms (λ3σ2) exhibited the characteristic of serving as unique hybrid ligands.
A chiral Ni(II) complex-catalyzed asymmetric [3 + 2] cycloaddition/oxidation sequential reaction was reported, which enables the construction of both C–C five–six-membered and C–N five–five-membered axially chiral arylpyrazole atropisomers.
Deuterium incorporation in pyrazoles and the corresponding alkynylhydrazones from the Cu(I)-catalysed reaction between chlorohydrazones and terminal acetylenes depends on the reaction conditions, which reconciles apparently conflicting literature data.