Chiral Iodotriptycenes: Synthesis and Catalytic Applications

Abstract

New iodotriptycenes, including some chiral derivatives, have been synthesised, and their catalytic potential towards oxidative transformations has been investigated. The enantioselectivities observed in the products using chiral iodotriptycene catalysts are low, probably owing to the large distances between the coordinating groups and the iodine moieties in these compounds.

Catalytic stereoselective synthesis involving hypervalent iodine-based chiral auxiliaries

“…The corresponding spirocyclic products 41 was isolated in moderate yields with enantiomeric excess only up to 6% (Scheme 9). 69…”

“…The corresponding spirocyclic products 41 was isolated in moderate yields with enantiomeric excess only up to 6% (Scheme 9). 69 Gong and coworkers constructed spirooxindoles 44 via the oxidative spirocyclization of 1-hydroxy-N-aryl-2-naphthamides 42 employing chiral iodoarene 43 as the precatalyst (Scheme 10). 70 A facile synthesis of a library of spirooxindoles 44 were achieved in distinguished yields with up to 92% ee.…”

Progress in organocatalysis with hypervalent iodine catalysts

“…Moreover, triptycene based pre-catalysts 154–156 were also employed in the same reaction but could achieved only very limited success. 127…”

“…Moreover, triptycene based pre-catalysts 154-156 were also employed in the same reaction but could achieved only very limited success. 127 Wirth and co-workers developed the synthesis of novel iodotriptycenes 154-156 and employed them as precatalyst for the intramolecular dearomatisation of naphthols 152. The spirocyclic product 153 was obtained in moderate yields with only up to 6% ee (Scheme 41).…”

“…The spirocyclic product 153 was obtained in moderate yields with only up to 6% ee (Scheme 41). 127 Gong and co-workers described an elegant method for the construction of spirooxindoles 159 by an intramolecular dearomatisation of 1-hydroxy-N-aryl-2-naphthamides 158 using chiral iodoarene 157 as precatalyst (Scheme 42). 128 This is the first example of an enantioselective dearomatisation of 1hydroxy-N-aryl-2-naphthamides 158 providing a facile access to a library of spirooxindoles 159 in good yields with up to 92% ee.…”