82255-65-0Relevant articles and documents
Synthetic Utility of Arylmethylsulfones: Annulative π-Extension of Aromatics and Hetero-aromatics Involving Pd(0)-Catalyzed Heck Coupling Reactions
Sankar, Elumalai,Raju, Potharaju,Karunakaran, Jayachandran,Mohanakrishnan, Arasambattu K.
, p. 13583 - 13593 (2017/12/26)
A straightforward and general method for the synthesis of annulated thiophene, dibenzothiophene, and carbazoles analogues has been achieved involving alkylation of 2-bromo-1-(phenylsulfonylmethyl)arene/heteroarene with arylmethyl bromides/heteroarylmethyl bromides using t-BuOK as a base in DMF, followed by Pd(0)-mediated intramolecular Heck coupling in the presence of K2CO3 in DMF at 80-140 °C. The attractive feature of this protocol is that a wide variety of π-conjugated heterocycles could be readily accessed by an appropriate choice of arylmethylsulfones and benzylic bromides.
Electrophilic chemistry of thia-PAHs: Stable carbocations (NMR and DFT), S-alkylated onium salts, model electrophilic substitutions (nitration and bromination), and mutagenicity assay
Laali, Kenneth K.,Chun, Joong-Hyun,Okazaki, Takao,Kumar, Subodh,Borosky, Gabriela L.,Swartz, Carol
, p. 8383 - 8393 (2008/03/13)
(Chemical Equation Presented) First examples of stable carbocations are reported from several classes of thia-PAHs with four fused rings, namely, benzo[b]naphtho[2,1-d]thiophene (1) and its 3-methoxy derivative (2), phenanthro[4,3-b]thiophene (3) and its 7-methoxy (4), 10-methoxy (5), and 9-methoxy (6) derivatives, phenanthro[3,4-b]thiophene (7) and its 7-methoxy (8) and 9-methoxy (9) derivatives, and 3-methoxybenzo[b]naphtha[1,2-d]thiophene (11). In several cases, the resulting carbocations were also studied by GIAO-DFT. Charge delocalization modes in the resulting carbocations were probed, A series of S-alkylated onium tetrafluoroborates, namely, 1Me+, 1Et+, 2Et+, and 7Me+ (from 1, 2, and 7), 10Me+ and 10Et+ (from benzo[b]naphtha[1,2-d]thiophene 10), 12Me+ and 12Et+ (from phenanthro[3,2-b][1]benzothiophene 12), 13Me+ (from 3-methoxyphenanthro[3,2-b]benzothiophene 13), 14Me+ (from phenanthro[4,3-b][1]-benzothiophene 14), and 15Me + (from 3-methoxyphenanthro[4,3-b][1]benzothiophene 15), were synthesized. PAH-sulfonium salts 1Me+, 1Et+, 10Me +, 10Et+, 12Me+, and 14Me+ proved to be efficient akylating agents toward model nitrogen nucleophile receptors (imidazole and azaindole). Facile transalkylation to model nucleophiles (including guanine) is also supported by favorable reaction energies computed by DFT. Ring opening energies in thia-PAH-epoxides from 1, 3, and 7 and charge delocalization modes in the resulting carbocations were also evaluated. The four-ring-fused thia-PAHs 1, 2, 3, 4, 5, 7, 8, and 11 are effectively nitrated under extremely mild conditions. Nitration regioselectivity corresponds closely to protonation under stable ion conditions. Bromination of 4 and 6 is also reported. Comparative mutagenicity assays (Ames test) were performed on 1 versus 1NO2, 5 versus 5NO2, and 11 versus 11NO2. Compound 5NO2 was found to be a potent direct acting mutagen.
Thiophene analogues of carcinogenic polycyclic hydrocarbons. Elbs pyrolysis of various aroylmethylbenzo[b]thiophenes
Croisy,Mispelter,Lhoste,et al.
, p. 353 - 359 (2007/10/02)
The synthesis of two benzonaphthothiophenes and of four benzophenanthrothiophenes through Elbs cyclodehydration of ortho-methylated aroylbenzo[b]thiophenes is described. The occurrence of a rearrangement of the thiophene ring in the course of the cyclization is discussed as well as the influence of the temperature on a concurrent cyclodehydration process. Several of these poly-condensed thiophenes were found to be carcinogenic in mice.
