Search

Herein, we describe a one-pot aminoalkylation of styrene derivatives with boronic acids (BAs) and boronic acid pinacol esters as radical precursors for the synthesis of complex secondary amines in moderate to high yields through a mild and easily accessible organophotoredox-catalytic four-component reaction. Additionally, we report for the first time in a photoredox process the activation of alkyl boronic acid derivatives by imines, which play a dual role in the reaction as both substrate and Lewis base activator. The protocol applicability was greatly enhanced by its successful adaptation to photoflow reactors.

Herein, we describe a methodology to construct polycyclic pyrrolophenanthridones with an (amino)alkyl side chain that involves visible-light-induced decarboxylative radical addition for the intermolecular dearomatization of indoles and subsequent photoinduced C(sp 2 )-X bond activation via photoexcited ketones for an intramolecular cyclization cascade. Carboxylic acids serve both as a radical source toward indole dearomatization and as reductants to initiate an electron transfer with photoexcited N -acylindole derivatives in the reaction toward pyrrolophenantridone skeletons, which occurs under mild reaction conditions with good functional group tolerance.

A mild visible-light-driven palladium-catalyzed radical tandem dearomatization of indoles with unactivated alkenes is described with moderate to good yields and good to excellent diastereoselectivities. Under visible-light irradiation, the photoexcited state of the palladium complex was formed, which could transfer a single electron to N -(2-bromobenzoyl)indoles, leading to a hybrid palladium radical chemistry. This provides efficient and atom-economical access to diverse 2,3-disubstituted indoline derivatives.

A novel access to spiro[indoline-3,2'-pyrrole]-2,5'-diones is presented via a palladium-catalyzed post-Ugi cascade cyclization approach involving a Buchwald-Hartwig/Michael reaction sequence. The method allows the easy construction of a library of spirooxindoles in moderate to good yields starting from readily available precursors. In addition, alkynoic acids are replaced with α,β-unsaturated acids leading to variably substituted spirooxindoles.

A unique synergistic combination of lipase and ionic liquid [hmim]Br is reported for metal-free H(2)O(2) activation, which is the first example of biocatalytic promiscuity of CAL-B for chemoselective oxidation of aryl alcohols/acetates. The catalytic system exhibits excellent functional group compatibility under neutral conditions besides reusability up to ten cycles thereby making the process economically and environmentally viable.