Under mild conditions and without the need of inert gas protection, a Rh-catalyzed rearrangement of -divinylcyclopropanes to form 1,5-disubstituted 1,4-cycloheptadienes has been developed and is disclosed here. This reaction can expedite the synthesis of challenging seven-membered carbocycles.
View Article and Find Full Text PDFThe Pictet-Spengler type condensation of tryptamine derivatives and aldehydes or ketones is a classic reaction, and has been previously applied to assemble indole-annulated 5-, 6- and 8-membered heterocyclic rings. In this work, we further expand the synthetic scope of this reaction to the 7-membered azepino[4,5-]indole skeleton through the direct C-H functionalization of 2-alkyl tryptamines, in which the non-activated methylene group participates in a 7-membered ring formation with aldehydes. By combining this unprecedented ring-forming process with a second C-H olefination at the same carbon, the concise total synthesis of natural products ngouniensines is achieved, demonstrating the synthetic potential of the developed chemistry in simplifying retrosynthetic disconnections.
View Article and Find Full Text PDFMulti-source evidence fusion aims to process and combine evidence from different sources to support rational and reliable decision-making. The evidential reasoning (ER) approach is a helpful method to deal with information from multiple sources with uncertainty. It has been widely used in business analytics, healthcare management, and other fields for optimal decision-making.
View Article and Find Full Text PDFReport here is a Rh-catalyzed [4+3]/[4+1] cycloaddition of diene-vinylcyclopropanes (diene-VCPs) and carbon monoxide to access compounds with angular 5/7/5 tricyclic skeleton found in natural products. The reaction has broad scope and further transformation of the [4+3]/[4+1] cycloadduct was also investigated. How this [4+3]/[4+1] reaction occurs and why its competing [4+3] reaction is disfavored have been investigated computationally.
View Article and Find Full Text PDFPurpose: Nanomaterial-based drug-delivery systems allowing for effective targeted delivery of smallmolecule chemodrugs to tumors have revolutionized cancer therapy. Recently, as novel nanomaterials with outstanding physicochemical properties, boron nitride nanospheres (BNs) have emerged as a promising candidate for drug delivery. However, poor dispersity and lack of tumor targeting severely limit further applications.
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