Acylated 2‐(N‐arylaminomethylene)benzo[b]thiophene‐3(2H)‐Ones: Molecular Switches with Varying Migrants and Substituents

Abstract

Synthesis and properties of photochromic acylated 2-(N-arylaminomethylene)benzo[b]thiophene-3(2H)-ones are described. Their structure largely depends on the nature of acyl migrant and in a less degree on N-aryl substituent.

Acylotropic intramolecular rearrangements of keto enamines of benzo[b]-annelated heterocycles

“…A study of keto enamines 1 (X = S, R 2 = H) with a series of substituents in the aroyl migrating group COR 1 (R 1 = Ph, 4-MeC 6 H 4 , 4-ClC 6 H 4 , 4-O 2 NC 6 H 4 ) as well as in the N-aryl fragment (X = S, R 1 = Me, R 2 = NMe 2 , OMe, Me, I, Br, Cl, F, CN, COMe, NO 2 ) ( Table 2) [11] is of especial interest. Table 2 shows that increasing electron-withdrawing properties of the substituent at position 4 of the aroyl migrating group diminish the quantum yield of the N→O acyl transfer photoreaction to virtually zero.…”