6774-49-8Relevant academic research and scientific papers
Synthesis of 2-substituted benzo[: B] thiophenes via gold(i)-NHC-catalyzed cyclization of 2-alkynyl thioanisoles
Dillon, Christopher C.,Keophimphone, Bagieng,Sanchez, Melissa,Kaur, Parveen,Muchalski, Hubert
, p. 9279 - 9284 (2019/01/03)
Benzo[b]thiophene heterocycles are important components of many important small molecule pharmaceuticals and drug candidates as well as organic semiconducting materials. Many methods have been developed for the construction of a benzo[b]thiophene core via cyclization reaction of alkynes. Although few catalytic reactions were disclosed, most methods rely on stoichiometric activation of alkynes. Here we report an efficient method for the synthesis of 2-substituted benzo[b]thiophenes from 2-alkynyl thioanisoles catalyzed by a gold(i)-IPr hydroxide that is applicable to a wide range of substrates with diverse electronic and steric properties. Additionally, we demonstrate experimentally that the acid additive and its conjugate base are essential to catalyst turnover.
Potassium Hydroxide/Dimethyl Sulfoxide Superbase-Promoted Transition Metal-Free Synthesis of 2-Substituted Benzothiophenes under Visible Light
Gao, Li,Chang, Bin,Qiu, Wenzhao,Wang, Lele,Fu, Xianzhi,Yuan, Rusheng
, p. 1202 - 1207 (2016/04/26)
A potassium hydroxide/dimethyl sulfoxide (KOH/DMSO) superbase-promoted method for the synthesis of 2-substituted benzothiophenes has been developed via photoinduced intermolecular annulation of 2-halothioanisoles with terminal alkynes at ambient temperature. The present protocol uses commercially available 2-halothioanisoles as substrates and visible light as energy force, which offers a wide range of benzothiophenes regioselectively in moderate to good yields. Such a facile and effective transformation will provide an environment-friendly approach to the synthesis of benzothiophene derivatives.
Alkylations of Arylboronic Acids including Difluoroethylation/Trifluoroethylation via Nickel-Catalyzed Suzuki Cross-Coupling Reaction
Zhang, Xiaofei,Yang, Chunhao
supporting information, p. 2721 - 2727 (2015/09/01)
An efficient alkylation method of functionalized alkyl halides under mild nickel-catalyzed C(sp3)-(sp2) Suzuki cross-coupling conditions is described. The features of this approach are excellent functional group compatibility, low cost nickel catalyst, and the use of a mild base. This is also the first successful example of the nickel-catalyzed direct 2,2-difluoroethylation or 2,2,2-trifluoroethylation of aryl-/heteroarylboronic acids.
Cobalt-Catalyzed Negishi Cross-Coupling Reactions of (Hetero)Arylzinc Reagents with Primary and Secondary Alkyl Bromides and Iodides
Hammann, Jeffrey M.,Haas, Diana,Knochel, Paul
supporting information, p. 4478 - 4481 (2015/04/14)
We report a cobalt-catalyzed cross-coupling of di(hetero)arylzinc reagents with primary and secondary alkyl iodides or bromides using THF-soluble CoCl2·2 LiCl and TMEDA as a ligand, which leads to the corresponding alkylated products in up to 88% yield. A range of functional groups (e.g. COOR, CN, CF3, F) are tolerated in these substitution reactions. Remarkably, we do not observe rearrangement of secondary alkyl iodides to unbranched products. Additionally, the use of cyclic TBS-protected iodohydrins leads to trans-2-arylcyclohexanol derivatives in excellent diastereoselectivities (up to d.r.=99:1).
Iron-catalyzed heterocycle and arene deprotonative alkylation
Tran, Ly Dieu,Daugulis, Olafs
supporting information; experimental part, p. 4277 - 4279 (2010/11/04)
Figure Presented. A method for iron-catalyzed deprotonative alkylation of arene C-H bonds by alkyl iodides and bromides has been developed. In the presence of an amide base, both primary and secondary alkyl halides can be coupled with furans, thiophenes, pyridine derivatives, and some electron-withdrawing-group containing arenes.
