Acid-Promoted Bicyclization of Diaryl Alkynes: Synthesis of 2<i>H</i>‑Indazoles with in Situ Generated Diazonium Salt as Nitrogen Source

An unprecedented transition-metal-free tandem bicyclization of diaryl alkynes has been disclosed, which provides a streamlined access to a range of polycyclic 2<i>H</i>-indazoles in high to excellent yields. The salient features of this reaction include readily available starting materials, good functional group compatibility, mild reaction conditions, no column chromatography, high bond-formation efficiency, and ease in further transformations. Notably, this is the first example for the synthesis of 2<i>H</i>-indazoles with in situ generated diazonium salt as the nitrogen source, and a mechanistic rationale involving an acid-promoted tandem diazonium salt formation/bicyclization process is discussed

Acid-Promoted Bicyclization of Diaryl Alkynes: Synthesis of 2<i>H</i>‑Indazoles with in Situ Generated Diazonium Salt as Nitrogen Source

An unprecedented transition-metal-free tandem bicyclization of diaryl alkynes has been disclosed, which provides a streamlined access to a range of polycyclic 2<i>H</i>-indazoles in high to excellent yields. The salient features of this reaction include readily available starting materials, good functional group compatibility, mild reaction conditions, no column chromatography, high bond-formation efficiency, and ease in further transformations. Notably, this is the first example for the synthesis of 2<i>H</i>-indazoles with in situ generated diazonium salt as the nitrogen source, and a mechanistic rationale involving an acid-promoted tandem diazonium salt formation/bicyclization process is discussed

Acid-Promoted Bicyclization of Diaryl Alkynes: Synthesis of 2<i>H</i>‑Indazoles with in Situ Generated Diazonium Salt as Nitrogen Source

An unprecedented transition-metal-free tandem bicyclization of diaryl alkynes has been disclosed, which provides a streamlined access to a range of polycyclic 2<i>H</i>-indazoles in high to excellent yields. The salient features of this reaction include readily available starting materials, good functional group compatibility, mild reaction conditions, no column chromatography, high bond-formation efficiency, and ease in further transformations. Notably, this is the first example for the synthesis of 2<i>H</i>-indazoles with in situ generated diazonium salt as the nitrogen source, and a mechanistic rationale involving an acid-promoted tandem diazonium salt formation/bicyclization process is discussed

Acid-Promoted Bicyclization of Diaryl Alkynes: Synthesis of 2<i>H</i>‑Indazoles with in Situ Generated Diazonium Salt as Nitrogen Source

An unprecedented transition-metal-free tandem bicyclization of diaryl alkynes has been disclosed, which provides a streamlined access to a range of polycyclic 2<i>H</i>-indazoles in high to excellent yields. The salient features of this reaction include readily available starting materials, good functional group compatibility, mild reaction conditions, no column chromatography, high bond-formation efficiency, and ease in further transformations. Notably, this is the first example for the synthesis of 2<i>H</i>-indazoles with in situ generated diazonium salt as the nitrogen source, and a mechanistic rationale involving an acid-promoted tandem diazonium salt formation/bicyclization process is discussed

Acid-Promoted Bicyclization of Diaryl Alkynes: Synthesis of 2<i>H</i>‑Indazoles with in Situ Generated Diazonium Salt as Nitrogen Source

An unprecedented transition-metal-free tandem bicyclization of diaryl alkynes has been disclosed, which provides a streamlined access to a range of polycyclic 2<i>H</i>-indazoles in high to excellent yields. The salient features of this reaction include readily available starting materials, good functional group compatibility, mild reaction conditions, no column chromatography, high bond-formation efficiency, and ease in further transformations. Notably, this is the first example for the synthesis of 2<i>H</i>-indazoles with in situ generated diazonium salt as the nitrogen source, and a mechanistic rationale involving an acid-promoted tandem diazonium salt formation/bicyclization process is discussed

Acid-Promoted Bicyclization of Diaryl Alkynes: Synthesis of 2<i>H</i>‑Indazoles with in Situ Generated Diazonium Salt as Nitrogen Source

An unprecedented transition-metal-free tandem bicyclization of diaryl alkynes has been disclosed, which provides a streamlined access to a range of polycyclic 2<i>H</i>-indazoles in high to excellent yields. The salient features of this reaction include readily available starting materials, good functional group compatibility, mild reaction conditions, no column chromatography, high bond-formation efficiency, and ease in further transformations. Notably, this is the first example for the synthesis of 2<i>H</i>-indazoles with in situ generated diazonium salt as the nitrogen source, and a mechanistic rationale involving an acid-promoted tandem diazonium salt formation/bicyclization process is discussed

Transition-Metal-Free Fluoroarylation of Diazoacetamides: A Complementary Approach to 3‑Fluorooxindoles

An efficient transition-metal-free fluoroarylation reaction of <i>N</i>-aryl diazoacetamides with NFSI (<i>N</i>-fluoro­benzene­sulfonimide) is described. This reaction directly provides 3-fluorooxindole derivatives in yields of 67–93% with high selectivity via a carbene-free process under mild reaction conditions