Palladium-Catalyzed Intramolecular Selenocarbamoylation of Alkynes with Carbamoselenoates: Formation of α-Alkylidene-β-lactam Framework
摘要:
Pd-catalyzed intramolecular selenocarbamoylation of alkynes leading to alpha-alkylidene-beta-lactams was developed. This reaction can be applied to thiocarbamoylation and to the synthesis of delta- and epsilon-lactams and a cyclobutanone.
Lanthanide‐catalyzed alkynyl exchange through C−C single‐bondcleavage assisted by a secondary amino group is reported. A lanthanide amido complex is proposed as a key intermediate, which undergoes unprecedented reversible β‐alkynyl elimination followed by alkynyl exchange and imine reinsertion. The in situ homo‐ and cross‐dimerization of the liberated alkyne can serve as an additional driving force
Palladium-Catalyzed Carbo-Oxygenation of Propargylic Amines using in Situ Tether Formation
作者:Phillip D. G. Greenwood、Erwann Grenet、Jerome Waser
DOI:10.1002/chem.201900020
日期:2019.2.26
chiral auxiliaries, and catalysts. This work reports a new method for the palladium‐catalyzed oxyalkynylation and oxyarylation of propargylic amines. The reaction is perfectly regioselective based on the in situ introduction of a hemiacetal tether derived from trifluoroacetaldehyde. cis‐Selective carbo‐oxygenation was achieved for terminal alkynes, whereas internal alkynes gave trans‐carbo‐oxygenation products
complex. In particular, by employing an amphiphilic dendritic NHC–gold(I) complex having penta(ethylene glycol) units at the peripheral layer as a catalyst, the aqueous media carboxylative cyclization of propargylicamines proceeded smoothly to provide the corresponding 2-oxazolidinone at room temperature under atmospheric pressure of CO2.
Unusual Missing Linkers in an Organosulfonate-Based Primitive–Cubic (pcu)-Type Metal–Organic Framework for CO<sub>2</sub> Capture and Conversion under Ambient Conditions
作者:Guiyang Zhang、Huimin Yang、Honghan Fei
DOI:10.1021/acscatal.7b04189
日期:2018.3.2
organosulfonate-based metal–organicframework (MOF) with a defective primitive–cubic (pcu) topology was successfully synthesized. The unusual missing linkers, along with the highest permanent porosity (∼43%) in sulfonate-MOFs, offer a versatile platform for the incorporation of alkynophilic Ag(I) sites. The cyclic carboxylation of alkyne molecules (e.g., propargyl alcohol and propargyl amine) into α-alkylidene