Visible-light-driven metal-free C-H functionalization: access to new bioactive tetrahydroisoquinoline-butenolide hybrids via domino amine oxidation/vinylogous mannich reaction

An efficient metal-free visible-light-driven two-step domino reaction towards new bioactive tetrahydroisoquinoline-butenolide hybrid compounds was developed for the first time. The combination of fluorescein as photosensitizer and thiourea as an additive was found to be the most effective way to promote an aerobic amine oxidation/vinylogous Mannich domino reaction sequence with yields up to 97% for a broad substrate scope. Both experimental and computational evidence supported the crucial role of singlet oxygen in the developed C H functionalization reaction. Furthermore, the data suggest that thiourea is essential due to its ability to act as an electron-transfer mediator and/or scavenger of reactive oxygen species. In addition, in vitro studies of tetrahydroisoquinoline-butenolide hybrid compounds demonstrated their high antischistosomal and anti-cancer activities

ELECTROCHEMICAL DATA FOR EVALUATION OF PRACTICALLY IMPORTANT PROPERTIES OF ORGANIC AND ORGANOMETALLIC COMPOUNDS

The research was supported by the Ministry of Science and Higher Education of the Russian Federation at FRC Kazan Scientific Center (grant No. 075-15-2022-1128)

The Baldwin rules : revised and extended

The Baldwin rules constitute one of the clearest examples of the success which can be obtained through the application of stereoelectronic concepts to reaction design. With thousands of examples, the predictive power of these rules is inarguable. However, time has revealed a number of exceptions and gray areas within these rules, leading to extensions and revisions. In this review, we will present an overview of how subsequent studies of ring closure have clashed with several of Baldwin's predictions, leading to the revision of some classes of ring closure (alkyne cyclizations, electrophilic closures, etc.). We also discuss for which the original rules were vague (epoxides) or absent (promoted cyclizations), and the evidence revealed since Baldwin's work that has allowed for a better understanding of these ambiguities. With the concise summation of these amendments, this review aims to present an overview of the understanding of cyclization reactions to date. For further resources related to this article, please visit the WIREs website

Polyaromatic Ribbon/Benzofuran Fusion via Consecutive Endo Cyclizations of Enediynes

The Sonogashira/5-<i>endo-dig</i>/6-<i>endo-dig</i> cascade fuses a polycyclic aromatic backbone to the electron-rich furan subunit. The transformation proceeds in modest yields as a one-pot reaction. Efficiency of the full cascade is increased by removal of base prior to the addition of gold catalyst. Under these conditions, conversion to the full cascade products is achieved in nearly quantitative yields without purification of the intermediate products. Extension of the cascade toward triynes opens access to benzofuran-fused chrysene derivatives