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Gold‐catalyzed [4+3]‐Annulations of Benzopyriliums with Vinyldiazo Carbonyls to Form Bicyclic Heptatriene Rings with Skeletal Rearrangement
Author(s) -
Sekar Kulandai Raj Antony,
Liu RaiShung
Publication year - 2020
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.202000292
Subject(s) - chemistry , diazo , alkyl , bicyclic molecule , ketone , annulene , cycloaddition , catalysis , medicinal chemistry , ring (chemistry) , methyl vinyl ketone , stereochemistry , organic chemistry
We report gold catalyzed [4+3]‐annulations between benzopyriliums and 3‐alkyl‐2‐diazo‐3‐vinyl carbonyls, yielding 7 H ‐benzo[7]annulene products efficiently. Notably, the carbon skeletons of resulting 7 H ‐benzo[7]annulenes are structurally rearranged, accompanied by migrations of their alkyl and ketone motifs. Apart from applicable substrates over a wide scope, these annulatios are applicable to pyriliums and 3‐alkyl‐2‐diazo‐3‐vinyl esters to increase their reaction significance. We postulate a mechanism involving an initial [4+2]‐cycloaddition between benzopyriliums and 3‐alkyl‐2‐diazo‐3‐vinyl carbonyl species, followed by formation of gold carbenes to induce a ring expansion and group migrations.