Search

An efficient diastereoselective allylation of various carbonyl compounds with cyclic allylic halides by using commercially available bismuth powder in the presence of LiI was developed. Among all the metals screened, bismuth was found to be the best mediator for the transformation. The reactions involving various cyclic allylic halides proceeded smoothly at room temperature to produce the desired homoallylic alcohols in good to excellent yields with high diastereoselectivities (>99:1 dr). Reversed diastereoselectivity was obtained when carbonyl substrate (e. g., 2-pyridinecarboxaldehyde, glyoxylic acid) containing chelating substituent was used in the allylation reaction. In addition, the reactions involving acyclic (E)-cinnamyl bromide as substrate worked equally well with high diastereocontrol. (Figure presented.). Nanyang Technological University We gratefully acknowledge the financial support from Nanj-ing Tech University (Start-up Grant No. 39837118, 39837101,and 39837146), the SICAM Fellowship from Jiangsu NationalSynergetic Innovation Center for Advanced Materials, Post-graduate Research&Practice Innovation Program of JiangsuProvince (No. KYCX18_1075), and Nanyang Technological University.t

A convenient photoredox‐catalyzed defluorinative trifluoromethylation of α‐trifluoromethyl alkenes and gem‐difluoroalkenes is developed. The reactions proceeded efficiently via trifluoromethyl radical addition followed by β‐fluorine elimination process, providing a new entry to multifluorinated alkenes in moderate to good yields with excellent stereoselectivity. Ministry of Education (MOE)

The hydration of α,β-unsaturated ketones with water proceeded efficiently in the presence of In(OTf)3 (20 mol%) in aqueous media to afford synthetically versatile β-hydroxyketones in moderate to good yields with good functional group compatibility. The method also can be extended to the hydroalkoxylation of α,β-unsaturated ketones with various alcohols for the efficient synthesis of β-alkoxyketones as well as tetrahydrofuran derivatives.