This discovery illustrates selective meta C-H bond activation from multiple non-equivalent C-H bonds present in medicinally relevant arylethanesulfonic acid and the 2-arylpropanoic acid moiety using ...weakly coordinating nitrile as a directing group. Transformation of the meta olefinated compounds to important organic molecules has been demonstrated. Efforts were made to obtain mechanistic detail of the meta C-H bond functionalization reaction.
Selective meta-C–H activation of arenes to date has met with a limited number of functionalizations. Expanding the horizon of meta-C–H functionalization, herein we disclose an unprecedented ...meta-silylation and -germanylation protocol by employing a simple nitrile-based directing template. Longer linkers between the target site and the directing template were successfully explored for meta-silylation (sp2-ε and sp2-ζ). Additionally, synthetic utility was demonstrated with several postsynthetic elaborations and with a formal synthesis of TAC101, a promising drug for the treatment of lung cancer.
A number of pharmaceutical compounds possess an arylated 2-pyridone moiety. The existing reports using expensive starting materials and/or superstoichiometric metal salts have prompted us to explore ...a possible user-friendly method for their synthesis. In this report, we demonstrate an easy-to-handle reaction condition with an iron catalyst for the exclusive generation of C-3-arylated pyridone via C–H functionalization.
An economical approach to α‐CF3‐substituted ketones, which are important intermediates in synthetic and medicinal chemistry, employs olefins and the readily available Langlois reagent (CF3SO2Na). The ...reaction is operationally simple, proceeds at room temperature, and exhibits an excellent tolerance toward a wide variety of functional groups.
An azo armed Schiff base chemosensor was synthesized based on a naphthalene fluorophore, which transduces greenish-yellow emission by complexing with Al3+. It emits greenish-yellow fluorescence ...through restricted C=N isomerization, chelation-enhanced fluorescence, and the photo-induced electron transfer mechanism. The clear visible transformation of the achromatic ligand to a chromatic ligand by the 1 : 1 complexation with Al3+ is substantiated by ESI-MS spectra. 1H NMR, 13C NMR, and FTIR spectroscopies are used to characterize the HL. The selectivity of the HL for Al3+ in the presence of other metal ions was investigated through absorbance and fluorescence spectroscopies. The average lifetimes of HL and L–Al3+ have been evaluated using a time-resolved photoluminescence experiment to explore the sensing mechanism. The Al3+ sensing mechanism was also established by density functional theory calculations. A reversibility experiment was performed, demonstrating that Al3+ binding to HL is reversible. The pH variation on luminescence affirms that the HL can survive in physiological pH. Finally, the lower limit of detection of 5.4 × 10−7 and a good response in a cytotoxicity and cell imaging study confirm the usability of the ligand as an indelible signature of an effective biosensor for target Al3+.
Transition metal‐catalyzed decarbonylation is an essential paradigm of synthetic organic chemistry. Decarbonylation offers a unique pathway to decoding the skeletal structure of arenes and enabling ...easy synthesis of structurally complicated molecules. Due to the omnipresence of carbonyl groups in a wide array of synthetically important complex molecules, the variety and scope of these transformations are enormous. As a result, the development of transition metal catalysts in such a simple decarbonylation reaction ranks among one of the most important topics in synthetic organic chemistry. Transition metals that have been employed range from 3d metals like V to second‐row transition metals like Pd. The growing potential of this methodology has driven the pioneers of synthetic organic chemistry into delving into the details of this transition metal‐catalyzed decarbonylation pathways. This review aims to take the readers through the employment of transition metals in various decarbonylation processes developed by our group, sticking not only to the scope and diversification of synthetically complex molecules, but also enabling the readers to understand the mechanistic insights, through computational and kinetic studies put forward in such reaction protocol, hoping to pave the way for future organic chemists to delve and hopefully solve the unique problems associated with this protocol.
The growing potential of decarbonylation methodology has driven the pioneers of synthetic organic chemistry into delving into the details of this transition metal‐catalyzed decarbonylation pathways. This review aims to take the readers through the employment of transition metals in various decarbonylation processes developed by our group, sticking not only to the scope and diversification of synthetically complex molecules, but also enabling the readers to understand the mechanistic insights, through computational and kinetic studies put forward in such reaction protocol.
An intramolecular dehydrogenative (sp3)C–O bond formation in salicylamides can be initiated by an active Cu/O2 species to generate pharamaceutically relevant dihydro-oxazinones. Experimental ...findings suggest that stereoelectronic parameters in both coupling partners are controlling factors for site selectivity in bond formation. Mechanistic investigations including isotope labeling, kinetic studies helped to propose a catalytic cycle. The method provides a convenient synthesis of an investigational new medicine CX-614, which has potential in finding treatment for Parkinson’s and Alzheimer’s diseases.
Strong σ-coordination by a heteroatom containing directing group (DG) is one of the effective strategies for performing site-selective C–H functionalization. Despite tremendous progress in directed ...ortho-C–H functionalization, selective meta-C–H functionalization using strong σ-coordination remains extremely challenging. Herein, we introduce the 8-nitroquinoline-based DG to ensure the formation of a stable palladacycle which enables selective meta-alkenylation and acetoxylation of arenes. Kinetic experiments, ESI-MS, NMR, and DFT studies provided important information regarding the mechanism of the reaction. The scalability as well as diversification of the products have been examined and are expected to be beneficial in pharmaceutical and material sciences.
A general method for selective dehydroxymethylation has been discovered by using widely available Pd(OAc)(2). The present study offers a new synthetic strategy for the regioselective ...functionalization by employing the steric, electronic and coordinating nature of the hydroxymethyl (-CH(2)OH) group temporarily.
