Base-mediated ynone-isocyanide [3+2] cycloaddition: a general method to 2,3,4-tri-substituted 1-H-pyrroles and bis-pyrroles

Abstract

A transition-metal-free and base-promoted one-pot synthesis of 2,3,4-trisubstituted 1-H-pyrroles has been developed. The reaction occurs through the [3+2] cycloaddition of differently functionalized ynones and isocyanides. The reaction’s advantageous features are...

Visible light-driven highly atom-economical divergent synthesis of substituted fluorenols and cyclopropylcarbaldehydes

“…1 Moreover, it can facilitate the formation of pharmaceutical and bioactive scaffolds 2 and versatile intermediates in organic synthesis 3 and provide access to natural products 4 under sustainable reaction conditions. The construction of these motifs has drawn considerable attention for use in different reactions, including intermolecular–intramolecular cascade cyclization, 5 ring expansion/contraction, 6 transition-metal/metal-free catalysis, 7 and radical chemistry. 8 However, most of these preparative methods involve the multistep synthesis of starting precursors, generation of toxic waste, low atom economy, and harsh reaction conditions, limiting their applicability in synthetic organic chemistry.…”

Synthesis of Pyridin-2(1H)-imines via the Transformation of Conjugated Ynones

“…Indeed, conjugated ynones have gained great attention because of their wide application in organic synthesis. For example, it can undergo 1,4- or 1,2-nucleophilic addition (Scheme a), , [2 + 2] cycloaddition, [3 + 2] 1,3-dipolar cycloaddition, Diels–Alder-type cycloaddition (Scheme b), aldol reactions (Scheme c), and cyclization . However, these reactivity and synthetic applications of ynones were focused on the transformation of mono- or dual-functional groups, while the total transfunctionalization of conjugated ynones, such as the simultaneous addition reaction of the triple bond, transfunctionalization of the carbonyl group, and C–C cleavage of the alkyl carbonyl group, has not been well developed (Scheme d).…”