Aza-ortho-xylylenes in Organic Synthesis

Synthesis of quinolines and acridines by the reaction of 2-(perfluoroalkyl)anilines with lithium and Grignard reagents

“…It is the adduct 10 that undergoes intramolecular 6π-electron cyclization, as evidenced by the isolation and characterization of intermediate 4,4-disubstituted-3,4-dihydroquinoline [30]. The two methodologies discussed above are quite general in scope, and a large array of other substituted quinolines [29,[32][33][34][35][36][37][38] and fused quinolines including acridines [39,40] can easily be prepared by the reaction of 2 or 7 with various basic/nucleophilic reagents [41][42][43][44][45].…”

Synthesis of quinolines and acridines by the reaction of 2-(perfluoroalkyl)anilines with lithium and Grignard reagents

“…It is the adduct 10 that undergoes intramolecular 6π-electron cyclization, as evidenced by the isolation and characterization of intermediate 4,4-disubstituted-3,4-dihydroquinoline [30]. The two methodologies discussed above are quite general in scope, and a large array of other substituted quinolines [29,[32][33][34][35][36][37][38] and fused quinolines including acridines [39,40] can easily be prepared by the reaction of 2 or 7 with various basic/nucleophilic reagents [41][42][43][44][45].…”

Five‐Membered Heterocycles: 1,2‐Azoles. Part 2. Isoxazoles and Isothiazoles

“…The nitro derivatives are prepared in higher yields and under milder conditions (Scheme 9.74) [283]. Such compounds are used as precursors of aza-ortho-quinodimethanes (see Scheme 9.119 The key feature of these heterocycles is that they possess the typical properties of an aromatic system but contain a weak nitrogen-oxygen bond, which, under certain reaction conditions, particularly in reducing or basic conditions, is a potential site of ring cleavage.…”

Formation of Aza-ortho-quinone Methides Under Room Temperature Conditions: Cs2CO3 Effect

“…Corey first reported the use of aoQMs as useful reactive intermediates in 1999, and for more than a decade, this chemistry remained underexplored until our report in 2014 . While there are examples of aoQMs being formed as a result of pyrolysis, photolysis, with nonremovable stabilizing groups, or from even more reactive precursors, the difficulty of its generation under mild conditions have limited aoQMs as general electrophiles in catalysis and synthesis.…”

Synthesis of quinolines and acridines by the reaction of 2-(perfluoroalkyl)anilines with lithium and Grignard reagents

“…It is the adduct 10 that undergoes intramolecular 6π-electron cyclization, as evidenced by the isolation and characterization of intermediate 4,4-disubstituted-3,4-dihydroquinoline [30]. The two methodologies discussed above are quite general in scope, and a large array of other substituted quinolines [29,[32][33][34][35][36][37][38] and fused quinolines including acridines [39,40] can easily be prepared by the reaction of 2 or 7 with various basic/nucleophilic reagents [41][42][43][44][45].…”

Five‐Membered Heterocycles: 1,2‐Azoles. Part 2. Isoxazoles and Isothiazoles

“…The nitro derivatives are prepared in higher yields and under milder conditions (Scheme 9.74) [283]. Such compounds are used as precursors of aza-ortho-quinodimethanes (see Scheme 9.119 The key feature of these heterocycles is that they possess the typical properties of an aromatic system but contain a weak nitrogen-oxygen bond, which, under certain reaction conditions, particularly in reducing or basic conditions, is a potential site of ring cleavage.…”

Formation of Aza-ortho-quinone Methides Under Room Temperature Conditions: Cs2CO3 Effect

“…Corey first reported the use of aoQMs as useful reactive intermediates in 1999, and for more than a decade, this chemistry remained underexplored until our report in 2014 . While there are examples of aoQMs being formed as a result of pyrolysis, photolysis, with nonremovable stabilizing groups, or from even more reactive precursors, the difficulty of its generation under mild conditions have limited aoQMs as general electrophiles in catalysis and synthesis.…”

Synthesis of quinolines and acridines by the reaction of 2-(perfluoroalkyl)anilines with lithium and Grignard reagents

“…It is the adduct 10 that undergoes intramolecular 6π-electron cyclization, as evidenced by the isolation and characterization of intermediate 4,4-disubstituted-3,4-dihydroquinoline [30]. The two methodologies discussed above are quite general in scope, and a large array of other substituted quinolines [29,[32][33][34][35][36][37][38] and fused quinolines including acridines [39,40] can easily be prepared by the reaction of 2 or 7 with various basic/nucleophilic reagents [41][42][43][44][45].…”

Five‐Membered Heterocycles: 1,2‐Azoles. Part 2. Isoxazoles and Isothiazoles

“…The nitro derivatives are prepared in higher yields and under milder conditions (Scheme 9.74) [283]. Such compounds are used as precursors of aza-ortho-quinodimethanes (see Scheme 9.119 The key feature of these heterocycles is that they possess the typical properties of an aromatic system but contain a weak nitrogen-oxygen bond, which, under certain reaction conditions, particularly in reducing or basic conditions, is a potential site of ring cleavage.…”

Formation of Aza-ortho-quinone Methides Under Room Temperature Conditions: Cs2CO3 Effect

“…Corey first reported the use of aoQMs as useful reactive intermediates in 1999, and for more than a decade, this chemistry remained underexplored until our report in 2014 . While there are examples of aoQMs being formed as a result of pyrolysis, photolysis, with nonremovable stabilizing groups, or from even more reactive precursors, the difficulty of its generation under mild conditions have limited aoQMs as general electrophiles in catalysis and synthesis.…”