This tutorial review highlights new research in the area of pericyclic domino reactions. It is directed towards chemists interested in cascading reactions and the total synthesis of natural products. Concise approaches to natural frameworks are described, as well as the application of domino reactions in the context of target-oriented synthesis and total synthesis.
Thermal or microwave-mediated heating of 2- or 3-haloindoles with azoles (pK(a) < 8) provides a straightforward, metal-free, and environmentally friendly access to novel 2-(azol-1-yl)indoles. Furthermore, previously unknown 2,3-bis(azolyl-1-yl)indoles can be prepared from 2,3-dihaloindoles by sequential reaction with two distinct azoles. This operationally simple acid-catalyzed process delivers novel indole derivatives in fair to excellent yields and expands the chemical diversity of substitutions that can be introduced on this medicinally important scaffold.
Two key reactions in a rapid assembly of the tricyclic core of vinigrol are a stereoselective Claisen rearrangement and an intramolecular Diels–Alder reaction. The method paves the way for a total synthesis of this synthetically challenging and biologically interesting natural product.
The luminescence spectroscopy study and the determination of the photophysical parameters for the M-M'-bonded rhodium meso-tetraphenylporphyrin-tin(2,3,7,13,17,18-hexamethyl-8,12-diethylcorrole) complex, (TPP)Rh-Sn(Me6Et2Cor) 1, was investigated. The emission bands as well as the lifetimes (tau(e)) and the quantum yields (Phi(e); at 77 K using 2MeTHF as solvent) were compared with those of (TPP)RhI 2 (TPP = tetraphenylporphyrin) and (Me6Et2Cor)SnCl 3 (Me6Et2Cor = 2,3,7,13,17,18-hexamethyl-8,12-diethylcorrole) which are the two chemical precursors of 1. The energy diagram has been established from the absorption, fluorescence and phosphorescence spectra. The Rh(TPP) and Sn(Me6Et2Cor) chromophores are the energy donor (D) and acceptor (A), respectively. The total absence of fluorescence in 1 (while fluorescence is observed in the tin derivative 3) indicates efficient excited state deactivation, presumably due to heavy atom effect and intramolecular energy transfer (ET). The large decreases in tau(P) and Phi(P) of the Rh(TPP) chromophore going from 2 to 1 indicate a significant intramolecular ET in the triplet states of 1 with an estimated rate ranging between 10(6) and 10(8) s(-1). Based on the comparison of transfer rates with other related dyads that exhibit similar D-A separations and no M-M' bond, and for which slower through space ET processes (10(2)-10(3) s(-1)) operate, a through M-M' bond ET has been unambiguously assigned to 1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.