The α‐regioselective conjugate addition of allyl groups to activated alkenes is a poorly explored area of research. Herein, we report an α‐adduct and (E)‐isomer selective conjugate addition of allylsilanes to activated alkenes by visible‐light photoredox catalysis. The reaction involves allylic radicals that can be generated from allylsilanes through a photoinduced single‐electron transfer mechanism.magnified image

The development of a greener allylation reagent for α‐allylation of carbonyl compounds is of great necessity. Here we present allyltrimethylsilane as a novel allylation reagent in the photoredox‐catalyzed α‐allylation of carbonyl compounds such as ketones, esters, and amides. The reaction process shows good functional group tolerance and generates a good yield of the product. The reaction mechanism is a radical‐mediated reaction by photo‐induced single electron transfer.

Ah igh-yielding synthesis of a-acyloxyketones using aN -heterocyclic-carbene (NHC)-catalyzed, oxidative ring-opening of epoxides with aromatic aldehydes is described. This regioselective,o xidative process utilizes a Nbromosuccinimide( NBS)/DMSO combination as the oxidant system and Et 3 Na st he base under mild reaction conditions. Scheme1.NHC-catalyzed,o xidative ring-opening of epoxides with aromatic aldehydes.[a] R.

Carbon−carbon bond formation is an efficient approach for the synthesis of amino alcohols using two simple starting materials. Herein, we present a novel method for a divergent synthesis of β-amino ethers and β-amino alcohols in a sequential one-pot protocol under high-efficiency, mild, and metalor metal-free conditions. Especially, TMSCH 2 OPMP was developed as a synthetic equivalent of α-hydroxymethyl radical in an in situ photocatalyzed oxidative PMP group deprotection strategy under air. A preliminary mechanistic investigation provides evidence for reaction mechanism involving a photoinduced α-alkoxy methyl radical and superoxide.

Abstract:The convergent total synthesis of Sch725674 has been accomplished by starting from (R)-1,2-epoxyheptane and assembling five modules in a highly stereoselective manner to give the final product in 6.6 % overall yield. The same strategy was extended to the synthesis of its C-4 epimer. Key reactions of the synthetic pathway include a Jacobsen hydrolytic kinetic