Pd-Catalyzed Difluoromethylation of Vinyl Bromides, Triflates, Tosylates, and Nonaflates
作者:Dalu Chang、Yang Gu、Qilong Shen
DOI:10.1002/chem.201500551
日期:2015.4.13
Pd‐catalyzed difluoromethylation of di‐, tri‐ or tetra‐substituted vinyl bromides, triflates, tosylates and nonaflates under mild conditions is described. The reaction tolerates a wide range of functional groups, such as bromide, chloride, fluoride, ester, amine, nitrile, and protected carbonyl, thus providing a general route for the preparation of difluoromethylated alkenes.
A convenient method for the synthesis of Δ1,6-bicyclo[4.n.0]alken-2-ones
作者:Norihiko Watanabe、Keiji Tanino、Isao Kuwajima
DOI:10.1016/s0040-4039(99)01723-2
日期:1999.11
A convenient annulation method for the synthesis of bicyclic enones from cycloalkanones was developed. In the presence of a Pd(0) catalyst, enol triflates derived from ethyl 2-oxocycloalkanecarboxylates were treated with 3-(ethoxycarbonyl)propylzinc iodide to afford the corresponding diesters via a cross-coupling reaction. The diesters were easily transformed into Δ1,6-bicyclo[4.n.0]alken-2-ones through
Catalytic Enantioselective Nazarov Cyclization: Construction of Vicinal All-Carbon-Atom Quaternary Stereocenters
作者:Anais Jolit、Patrick M. Walleser、Glenn P. A. Yap、Marcus A. Tius
DOI:10.1002/anie.201403587
日期:2014.6.10
The diastereoselective asymmetric synthesis of vicinal all‐carbon‐atom quaternarystereocenters is a challenging problem in organic synthesis for which only few solutions have been described. A catalytic asymmetric Nazarovcyclization of fully substituted dienones that provides cyclopentenone derivatives with vicinalquaternarystereocenters in high optical purity and as single diastereoisomers is
Asymmetricallylic alkylation (AAA) is a powerful method for the formation of highly useful, non-racemic allylic compounds. Here we present a complementary enantioselective process that generates allylic lactones via π-acid catalysis. More specifically, a catalytic enantioselective dehydrative lactonization of allylicalcohols using a novel PdII-catalyst containing the imidazole-based P,N-ligand (S)-StackPhos