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A new radical relay approach for the efficient construction of alkylsulfonated indolo[2,1-a]isoquinoline-6(5H)-ones in moderate to good yields under mild conditions via SO2 insertion/Smiles rearrangement/intramolecular cyclization is developed. This approach utilizes 4-alkyl substituted Hantzsch esters as alkyl radical sources and further undergoes in situ SO2 insertion to obtain alkylsulfonyl radical species, which avoids the use of unstable alkyl sulfonyl chlorides and highly toxic sulfonyl hydrazides. Additionally, this method for the direct assembly of alkylsulfonated polycyclic molecule skeletons displays high chemical selectivity, broad substrate scope, and step-economy. [ABSTRACT FROM AUTHOR]

A direct visible‐light‐promoted radical‐triggered tandem cyclization of 1,7‐diene systems with cyclic sulfonium salts by using copper(I)‐based complexes as photoredox catalyst is developed. With this approach, a variety of sulfur‐containing polycyclic derivatives are prepared through alkylation/6‐exo‐trig cyclization/5‐exo‐trig cyclization of 1,7‐diene systems under mild conditions. In addition, the photoinduced copper‐catalyzed ring‐opening of cyclic sulfonium salts provides the alkyl radical intermediates, which prefers addition to the C−C double bond that connected to the aromatic ring rather than the electron‐deficient vinyl in 1,7‐dienes. Moreover, oxidation of the desired sulfur‐containing polycyclic products provides a strategy for the preparation of remote nitrogen‐fused polycyclic substituted sulfoxide or sulfone‐containing derivatives. [ABSTRACT FROM AUTHOR]

A novel strategy of visible‐light photoredox catalysis ipso‐annulation of activated alkynes with polychloroalkanes for the synthesis of 3‐polychloroalkyl spiro[4,5]trienones, which used 4‐methoxybenzenediazonium tetrafluoroborate salt as a hydrogen atom transfer reagent, is described. This polychloroalkylation/ spirocyclization of alkynes offers a widely range of 3‐polychloroalkyl‐spiro[4,5]trienone derivatives in high yields with a broad substrate scope via selective C(sp3)‐H homolytic cleavage. The results of controlled experiments showed that this method involves a radical process. The polyhaloalkyl radical species generated from intermolecular hydrogen atom transfer (HAT) between aryl radical and polychloroalkanes. [ABSTRACT FROM AUTHOR]

A simple and efficient oxidative‐promoted radical cascade annulation of ynone derivatives with ketones for the construction of a series of oxoalkyl‐substituted indenones in moderate to good yields is described. The control experiment results indicate that the oxidative acetmethylation/arylation of ynone derivatives involves a radical cascade cyclization process. This is an operationally simple and efficient protocol which will be attractive in organic synthesis chemistry. [ABSTRACT FROM AUTHOR]

A new biocatalyst PCL@UiO‐67(Zr) was successfully synthesized by immobilized lipases on metal–organic frameworks (MOFs) materials. Compare with free lipases, zirconium foundation organic framework material UiO‐67(Zr) modification on immobilized lipases Pseudomonas cepacia lipase (PCL) great boosts their enantioselectivity in the kinetic resolution racemic 4‐chloro‐mandelic acid (4‐ClMA) on the organic solvent. The acquired bio‐composite PCL@UiO‐67(Zr) was fully characterized by powder X‐ray diffraction (PXRD), Fourier transform infrared (FT‐IR) spectroscopy, N2 adsorption–desorption isotherm and aperture distribution map, and scanning electron microscopy (SEM). The catalytic performance of PCL@UiO‐67(Zr), such as temperature, reaction time, and lipase quantity, were deeply explored. The experiment results showed resolution racemic 4‐ClMA optimum conditions that 20 mmol/L of (R, S)‐4‐chloromandelic acid, 120 mmol/L vinyl acetate, 30‐mg immobilized lipases PCL@UiO‐67(Zr), 2 mL of MTBE, 500 rpm, and under the 55°C reaction 18 h. In this optimum conditions, c and eep could reach up to 47.6% and 98.7%, respectively. [ABSTRACT FROM AUTHOR]

A visible light initiated α-C(sp3)–H arylation of N-(benzyloxy)phthalimides with cyanopyridines for the construction of highly valuable pyridinyl-containing diarylmethanols, including bioactive motif-based analogues, is reported. This method enables arylation of the C(sp3)–H bonds adjacent to an oxygen atom through alkoxy radical formation by O–N bond cleavage, 1,2-hydrogen atom transfer (HAT), arylation and C–CN bond cleavage cascades, and offers a means to exploit 1,2-HAT modes to incorporate functional groups for constructing functionalized alcohols. [ABSTRACT FROM AUTHOR]