Base-promoted amide synthesis from aliphatic amines and ynones as acylation agents through C-C bond cleavage

Zinc-catalyzed C-H alkenylation of quinoline N-oxides with ynones: a new strategy towards quinoline-enol scaffolds

A zinc-catalyzed C-H alkenylation of quinoline N-oxides with ynones has been developed to rapidly assemble a broad collection of valuable quinoline-enol organic architectures. Uncommonly, this novel reaction involves C-H functionalization, and N-O, C-C and C[triple bond, length as m-dash]C bond cleavage in one operation, and leads exclusively to the formation of an enol rather than a keto product. Application of the enols generated was highlighted by further derivative transformation and preparation of a series of "BODIPY" analogues with high quantum yields (up to 86%).

CuII-Catalyzed Coupling with Two Ynone Units by Selective Triple and Sigma C-C and C-H Bond Cleavages

We report a new copper-catalyzed [2 + 2 + 1] annulation process through the selective cleavage of sigma and triple C-C and C-H bonds using two ynone units. This new methodology involves breaking multiple chemical bonds in a single operation, including C≡C, C-C, C-H, and N-O. These high-value adducts lead to a diverse collection of synthetically challenging trisubstituted indolizines by the simultaneous engagement of different bond-breaking events and show excellent fluorescence in green aqueous solutions.

Synthesis of 3-(2-quinolyl) chromones from ynones and quinoline N-oxides via tandem reactions under transition metal- and additive-free conditions

The synthesis of 3-(2-quinolyl) chromones from ynones and quinoline N-oxides via a sequential [3+2] cycloaddition/ring-opening/O-arylation reaction under transition metal- and additive-free conditions is reported.

Ruthenium(ii)-catalyzed chemoselective deacylative annulation of 1,3-diones with sulfoxonium ylides via C-C bond activation

The first successful example of deacylative annulation of 1,3-diones with sulfoxonium ylides was achieved through Ru(ii)-catalyzed C-C bond activation. The excellent chemoselectivity and broad substrate scope render this method a practical and versatile approach for the preparation of (hetero)aryl and alkenyl substituted furans, which are valuable units in many biologically active compounds and functional materials. A preliminary mechanistic study reveals that this process involves a deacylative α-ruthenation to generate key alkyl Ru(ii) intermediates with the release of a benzoic acid fragment.

Tuneable access to isoquinolines via a transition-metal-free C(sp3)–C(sp3) bond cleavage rearrangement reaction

A novel divergent synthesis of multi-substituted isoquinolines via C(sp³)–C(sp³) bond cleavage rearrangement reactions was realized.

Synthesis of 2-Aminopyridines via a Base-Promoted Cascade Reaction of N-Propargylic β-Enaminones with Formamides

N-Substituted formamides as nucleophiles react with in situ-generated 1,4-oxazepines from N-propargylic β-enaminones followed by spontaneous N-deformylation to deliver densely substituted 2-aminopyridines in good yields (31-88%). The formyl group is found to be a superior traceless activating group of free amines and would ultimately be removed in situ. This reaction proceeds smoothly at room temperature, in the presence of NaOH as sole additive, without protection from the atmosphere and generates H₂O and sodium formate as byproducts.

Oxidative C(sp3)–H amidation of tertiary arylamines with nitriles

The first amidation of tertiary arylamines with nitriles via a cascade dehydrogenation/heterocoupling/addition reaction has been developed.

Base-promoted C–C bond cleavage for the synthesis of 2,3,4-trisubstituted pyrroles from N-propargyl β-enaminones

The synthesis of 2,3,4-trisubstituted pyrroles via base-promoted C–C bond cleavage reaction of N-propargyl β-enaminones is reported.