Enantioselective Synthesis of Tertiary α,α-Diaryl Carbonyl Compounds Using Chiral <i>N,N′</i>-Dioxides under Umpolung Conditions
作者:Tae-Woong Um、Girim Lee、Seunghoon Shin
DOI:10.1021/acs.orglett.0c00333
日期:2020.3.6
addition of the chiral N,N'-dioxide into ynamides generated enolonium ions in situ which underwent enantioselective alkylation by indoles, pyrroles, and phenols, without racemization of the formed tertiary center. This external oxidant approach allows for the use of unmodified nucleophiles and does not leave trace groups from the oxidant, which significantly increases the synthetic efficiency and the
Regiospecific Hydroamination of Unsymmetrical Electron-Rich and Electron-Poor Alkynes with Anilines Catalyzed by Gold(I) Immobilized in MCM-41
作者:Dayi Liu、Quan Nie、Rongli Zhang、Mingzhong Cai
DOI:10.1002/adsc.201800621
日期:2018.10.18
heterogeneous gold(I)‐catalyzedregiospecifichydroamination of ynamides and propiolic acid derivatives with anilines has been achieved by using a diphenylphosphine‐functionalized MCM‐41‐supported gold (I) complex and AgNTf2 as catalysts under mild conditions, yielding the corresponding (E)‐N‐arylimines and (Z)‐enamines in good to excellent yields with broad substrate scope. The new heterogeneous gold(I) complex
Gold-Catalyzed Intermolecular [4+2] and [2+2+2] Cycloadditions of Ynamides with Alkenes
作者:Ramesh B. Dateer、Balagopal S. Shaibu、Rai-Shung Liu
DOI:10.1002/anie.201105921
日期:2012.1.2
As good as gold: Gold‐catalyzedintermolecular [4+2] cycloadditions of 2‐arylynamides with alkenes and gold‐catalyzed [2+2+2] cycloadditions of terminal ynamides with enol ethers have been developed (see scheme). The [4+2] cycloaddition is compatible with a range of alkenes and arylynamides and the [2+2+2] cycloaddition can also accommodate a variety of different arylynamide and enol ether substrates
Palladium-Catalyzed Cycloisomerization and Aerobic Oxidative Cycloisomerization of Homoallenyl Amides: A Facile and Divergent Approach to 2-Aminofurans
作者:Cungui Cheng、Shuiyou Liu、Gangguo Zhu
DOI:10.1021/acs.orglett.5b00464
日期:2015.3.20
including cycloisomerization and aerobic oxidative cycloisomerization of homoallenyl amides, is described. Varieties of functionalized 2-amino-5-alkylfurans and 2-amino-5-formylfurans can be selectively synthesized in good to excellent yields. Preliminary mechanistic studies show that peroxide may be a key intermediate for this Pd-catalyzed radical aerobic oxidative cycloisomerization of homoallenyl
Regiocontrolled Gold-Catalyzed [2+2+2] Cycloadditions of Ynamides with Two Discrete Nitriles to Construct 4-Aminopyrimidine Cores
作者:Somnath Narayan Karad、Rai-Shung Liu
DOI:10.1002/anie.201405312
日期:2014.8.18
Reported herein is the novel gold‐catalyzedintermolecular [2+2+2] cycloaddition of ynamides with two discrete nitriles to form monomeric 4‐aminopyrimidines, which are pharmaceutically important structural motifs. The utility of this new cycloaddition is demonstrated by the excellent regioselectivity obtained using a variety of ynamides and nitriles.