The Mechanistic Fate of the Anilino Moiety in the Rearrangement of α-Anilinoketones

Synthesis of unsymmetrical dibenzoquinoxaline discotic mesogensElectronic supplementary information (ESI) available: full synthetic and analytical details, POM images. See http://www.rsc.org/suppdata/cc/b4/b400998c/

“…9 In this manner, we were able to assemble compounds 1d-1f in four steps from veratraldehyde in average overall yields of 29%. Unfortunately, while the benzoin condensation has been used to cross-couple electronically disparate aldehydes, 15,16 it is not a viable method for the formation of benzil derivatives such as 1a-c, that have nearly identical functional groups on both rings.…”

Synthesis of the Indole Nucleus

“…94 318 Chapter I1 as extensions of the Bischler reaction. The Bischler reaction has been the subject of two reviews4.…”

“…[355][356][357] of the Brown and Mann mechanismzg1 or by transient epoxide formation (see pp. [331][332] according to Nelson's 318 The acetanilide moiety should be a better leaving group than the unacetylated amine, although the latter would be more readily protonated because it is a stronger base (compare 499 and 500). 499 Alkyl groups attached to the nitrogen atom of a-arylaminoketones are reported to increase the resistance of the a-arylaminoketone to isomerizationZg1 and also cause indolization to occur preferentially by a direct ring closure process.…”

Mechanistic considerations in the synthesis of 2-aryl-indole analogues under Bischler–Mohlau conditions

“…26 It should be noted that Vara and co-workers have evaluated another mechanistic possibility leading to formation of rearranged indole products (such as 8 ), through an interesting carbonyl-shift rearrangement of a ketone (such as 3 ) to an aldehyde prior to cyclization. 26–28 …”