15728-44-6Relevant articles and documents
Lewis acid mediated, mild C-H aminoalkylation of azolesviathree component coupling
Emmert, Marion H.,He, Cyndi Qixin,Shah, Akshay A.,Felten, Stephanie
, p. 3890 - 3897 (2021)
This manuscript reports the development of a mild, highly functional group tolerant and metal-free C-H aminoalkylation of azolesviaa three-component coupling approach. This method enables the C-H functionalization of diverse azole substrates, such as oxazoles, benzoxazoles, thiazoles, benzothiazoles, imidazoles, and benzimidazoles. DFT calculations identify a key deprotonation equilibrium in the mechanism of the reaction. Using DFT as a predictive tool, the C-H aminoalkylation of initially unreactive substrates (imidazoles/benzimidazoles) can be enabled through anin situprotecting/activating group strategy. The DFT-supported mechanistic pathway proposes key interactions between the azole substrate and the Lewis acid/base pair TBSOTf/EtNiPr2that lead to azole activation by deprotonation, followed by C-C bond formation between a carbene intermediate and an iminium electrophile. Two diverse approaches are demonstrated to explore the amine substrate scope: (i) a DFT-guided predictive analysis of amine components that relates reactivity to distortion of the iminium intermediates in the computed transition state structures; and (ii) a parallel medicinal chemistry workflow enabling synthesis and isolation of several diversified products at the same time. Overall, the presented work enables a metal-free approach to azole C-H functionalizationviaLewis acid mediated azole C-H deprotonation, demonstrating the potential of a readily available, Si-based Lewis acid to mediate new C-C bond formations.
Electrochemical Oxidative Amination of Sodium Sulfinates: Synthesis of Sulfonamides Mediated by NH4I as a Redox Catalyst
Jiang, Yang-Ye,Wang, Qing-Qing,Liang, Sen,Hu, Li-Ming,Little, R. Daniel,Zeng, Cheng-Chu
, p. 4713 - 4719 (2016)
An efficient protocol for the synthesis of sulfonamides via the electrochemical oxidative amination of sodium sulfinates has been developed. The chemistry proceeds in a simple undivided cell employing a substoichiometric amount of NH4I that serves both as a redox catalyst and a supporting electrolyte; in this manner additional conducting salt is not required. A wide range of substrates, including aliphatic or aromatic secondary and primary amines, as well as aqueous ammonia, proved to be compatible with the protocol. Scale-up was possible, thereby demonstrating the practicality of the approach. The electrolytic process avoids the utilization of external oxidants or corrosive molecular iodine and therefore represents an environmentally benign means by which to achieve the transformation.
Facile access to: N-formyl imide as an N-formylating agent for the direct synthesis of N-formamides, benzimidazoles and quinazolinones
Huang, Hsin-Yi,Liang, Chien-Fu,Lin, Xiu-Yi,Yen, Shih-Yao
supporting information, p. 5726 - 5733 (2020/08/21)
N-Formamide synthesis using N-formyl imide with primary and secondary amines with catalytic amounts of p-toluenesulfonic acid monohydrate (TsOH·H2O) is described. This reaction is performed in water without the use of surfactants. Moreover, N-formyl imide is efficiently synthesized using acylamidines with TsOH·H2O in water. In addition, N-formyl imide was successfully used as a carbonyl source in the synthesis of benzimidazole and quinazolinone derivatives. Notable features of N-formylation of amines by using N-formyl imide include operational simplicity, oxidant- A nd metal-free conditions, structurally diverse products, and easy applicability to gram-scale operation.
Cu-catalyzed dehydrogenative olefinsulfonation of Alkyl arenes
Li, Fangfang,Zhang, Guang'an,Liu, Yingguo,Zhu, Bingke,Leng, Yuting,Wu, Junliang
supporting information, p. 8791 - 8795 (2020/11/30)
A copper-catalyzed reaction protocol for the dehydrogenation of ethylbenzenes into styrene derivatives has been developed. This reaction procedure proceeded well under mild reaction conditions, providing a practical and efficient strategy for the rapid assembly of biologically and pharmaceutically significant molecules, such as vinyl sulfone. Simple alkyl arenes were functionalized via consecutive β-elimination in the presence of N-sulfonylbenzo[d]imidazole with broad substrate scope and good functional group tolerance.
