4-Trisubstituted pyrroles were synthesized from enolizable aliphatic aldehydes and primary aliphatic amines by using iodine as the dual Lewis acid/mild oxidant. In the presence of 3.0 equiv of TBHP, enolizable α,β-unsaturated aldehyde, for example, cocal reacted with aromatic primary amines to form C2-iodized N-arylpyrroles. An acetal-containing pyrrole was successfully prepared from 4-aminobutyraldehyde
Tandem Acid/Pd‐Catalyzed Reductive Rearrangement of Glycol Derivatives
作者:Tanno A. Schmidt、Benjamin Ciszek、Prasad Kathe、Ivana Fleischer
DOI:10.1002/chem.202000251
日期:2020.3.18
investigations show that the substrate undergoes rearrangement to an aldehyde under [1,2]-H-migration and cleavage of an oxygen-based leaving group. The leaving group is trapped as its formic ester, and the aldehyde is reduced and subsequently esterified to a formate. While the rearrangement to the aldehyde is catalyzed by sulfonic acids, the reduction step requires a unique catalyst system comprising
Tandem nucleophilic addition–Oppenauer oxidation of aromatic aldehydes to aryl ketones with triorganoaluminium reagents
作者:Ying Fu、Yanshou Yang、Helmut M. Hügel、Zhengyin Du、Kehu Wang、Danfeng Huang、Yulai Hu
DOI:10.1039/c3ob40642c
日期:——
In the presence of pinacolone, the in situ prepared triorganoaluminium reagents reacted with aromatic aldehydes to give ketones in moderate to high yield. We propose that the products are formed via a tandem organoaluminium reagents addition–Oppenauer oxidation sequence.
Palladium-Catalyzed Intermolecular Heck-Type Reaction of Epoxides
作者:Shenghan Teng、Malcolm E. Tessensohn、Richard D. Webster、Jianrong Steve Zhou
DOI:10.1021/acscatal.8b02029
日期:2018.8.3
palladium-catalyzed intermolecular Heck-type reaction of both cyclic and acyclic epoxides is reported with tolerance of typical polar groups and acidic protons. Suitable alkenes include styrenes, conjugate dienes, and some electron-deficient olefins. In reactions of aliphatic terminal epoxides, ring opening occurs selectively at terminal positions, and stereocenters of epoxides are fully retained. Mechanistic studies