Nitrogen analogs of o-xylylenes

Aza-ortho-xylylenes in Organic Synthesis

“…[22] Scheme 36 3,1-Benzoxazines, readily available from 2-aminobenzyl alcohol and carbonyl compounds, undergo retro-DielsϪ Alder reactions under FVT conditions, as was shown by trapping of the intermediate 9 formed from 2,2-pentamethylene-3,1-benzoxazine (147) with thiophenol, to give the aniline 148 (Scheme 37). [83] This result contradicted an earlier report [84] that claimed formation of N-alkenylaza-orthoxylylene 149 from 147 and its further electrocyclization through 150 to give the 2,3-disubstituted quinoline 151.…”

Visible‐Light‐Driven Aza‐ortho‐quinone Methide Generation for the Synthesis of Indoles in a Multicomponent Reaction

“…Traditional methods for the in situ formation of aza‐ o ‐QMs mainly rely on pyrolysis, UV photolysis, as well as base or Brønsted acid promoted 1,4‐elimination or tautomerization. In practice, pyrolysis and UV photochemical processes are rarely exploited in organic synthesis owing to the requirement of unstable precursors or their limited substrate scope and functional‐group tolerance.…”

“…[2] In contrast to the chemistry of o-QMs, which can be formed from ar ange of precursors, [3] the chemistry of aza-o-QMs has yet to be fully investigated as there are no general methods for their convenient generation.Tr aditional methods for the in situ formation of aza-o-QMs mainly rely on pyrolysis, [4] UV photolysis, [5] as well as base [6] or Brønsted acid [7] promoted 1,4-elimination or tautomerization. This process enables an efficient multicomponent reaction of 2-vinylanilines,h alides,a nd sulfur ylides,a nd has aw ide substrate scope and good functional group tolerance.…”

“…Tr aditional methods for the in situ formation of aza-o-QMs mainly rely on pyrolysis, [4] UV photolysis, [5] as well as base [6] or Brønsted acid [7] promoted 1,4-elimination or tautomerization. In practice,pyrolysis and UV photochemical processes are rarely exploited in organic synthesis owing to the requirement of unstable precursors or their limited substrate scope and functional-group tolerance.B rønsted base and acid mediated 1,4-elimination reactions of orthochloromethyl anilines [8] and ortho-amino benzhydryl alcohols [9] have recently attracted renewed interest in organic synthesis as powerful and benign methods for aza-o-QM generation.…”

Visible‐Light‐Driven Aza‐ortho‐quinone Methide Generation for the Synthesis of Indoles in a Multicomponent Reaction

“…Tr aditional methods for the in situ formation of aza-o-QMs mainly rely on pyrolysis, [4] UV photolysis, [5] as well as base [6] or Brønsted acid [7] promoted 1,4-elimination or tautomerization. In practice,pyrolysis and UV photochemical processes are rarely exploited in organic synthesis owing to the requirement of unstable precursors or their limited substrate scope and functional-group tolerance.B rønsted base and acid mediated 1,4-elimination reactions of orthochloromethyl anilines [8] and ortho-amino benzhydryl alcohols [9] have recently attracted renewed interest in organic synthesis as powerful and benign methods for aza-o-QM generation.…”