65690-69-9Relevant articles and documents
High-Throughput Discovery and Evaluation of a General Catalytic Method for N-Arylation of Weakly Nucleophilic Sulfonamides
Becica, Joseph,Hruszkewycz, Damian P.,Steves, Janelle E.,Elward, Jennifer M.,Leitch, David C.,Dobereiner, Graham E.
supporting information, p. 8981 - 8986 (2019/11/11)
Through targeted high-throughput experimentation (HTE), we have identified the Pd/AdBippyPhos catalyst system as an effective and general method to construct densely functionalized N,N-diaryl sulfonamide motifs relevant to medicinal chemistry. AdBippyPhos is particularly effective for the installation of heteroaromatic groups. Computational steric parametrization of the investigated ligands reveals the potential importance of remote steric demand, where a large cone angle combined with an accessible Pd center is correlated to successful catalysts for C-N coupling reactions.
Triple Mode of Alkylation with Ethyl Bromodifluoroacetate: N, or O-Difluoromethylation, N-Ethylation and S-(ethoxycarbonyl)difluoromethylation
Polley, Arghya,Bairy, Gurupada,Das, Pritha,Jana, Ranjan
supporting information, p. 4161 - 4167 (2018/09/21)
In this report, we have explored a triple mode of chemical reactivity of ethyl bromodifluoroacetate. Typically, bromodifluoroacetic acid has been used as a difluorocarbene precursor for difluoromethylation of soft nucleophiles. Here we have disclosed nucleophilicity and base dependent divergent chemical reactivity of ethyl bromodifluoroacetate. It furnishes lithium hydroxide and cesium carbonate promoted difluoromethylation of tosyl-protected aniline and electron-deficient phenols respectively. Interestingly, switching the base from lithium hydroxide to 4-N,N-dimethylamino pyridine (DMAP) tosyl-protected anilines afforded the corresponding N-ethylation product. Whereas, highly nucleophilic thiophenols furnished the corresponding S-carboethoxydifluoromethylation product via a rapid SN2 attack to the bromine atom prior to the ester hydrolysis. This mechanistic divergence was established through several control experiments. It was revealed that difluoromethylation reaction proceeds through a tandem in situ ester hydrolysis/decarboxylative-debrominative difluorocarbene formation and subsequent trapping by the soft nucleophile-NHTs or electron-deficient phenolic ?OH groups. In the presence of DMAP the hydrolysis of the ester is perturbed instead a nucleophilic attack at the ethyl moiety provides the N-ethylation product. Hence, besides the development of a practical base-promoted N-difluoromethylation of amines and electron-deficient phenols, divergent reactivity pattern of inexpensive and user-friendly ethyl bromodifluoroacetate has been explored. (Figure presented.).
Direct C-H amidation of benzoic acids to introduce meta- and para-amino groups by tandem decarboxylation
Lee, Donggun,Chang, Sukbok
, p. 5364 - 5368 (2015/03/30)
The Ir-catalyzed mild C-H amidation of benzoic acids with sulfonyl azides was developed to give reactions with high efficiency and functional-group compatibility. Subsequent protodecarboxylation of ortho-amidated benzoic acid products afforded meta- or para-substituted (N-sulfonyl)aniline derivatives, the latter being inaccessible by other C-H functionalization approaches. The decarboxylation step was compatible with the amidation conditions, enabling a convenient one-pot, two-step process. Without a trace: Carboxylic acids are used as traceless directing groups in the Ir-catalyzed direct C-H amidation of arenes with sulfonyl azides under mild conditions. The tandem protodecarboxylation of the ortho-amidated benzoic acid products afforded meta- or para-substituted (N-sulfonyl)anilines, which are difficult to obtain by other C-H functionalization approaches.
