Privilege Ynone Synthesis via Palladium-Catalyzed Alkynylation of “Super-Active Esters”
摘要:
A neat palladium-catalyzed alkynylation reaction was developed with "super-active ester" as the carbonyl electrophile, which provides a dean-and efficient synthetic protocol for a broad array Of ynone compounds under CO-, Cu-,, ligand-, and base-free conditions. The superior activity of triazine ester was rationalized by the strong electron;withdrawing ability and the unique affinity of triazine On palladium. A mechanistic experiment clearly demonstrated that the N-Pd coordination of triazine plays a crucial role for the highly efficient C-O activation.
(HAT) strategies within the framework of photoredox catalysis is highly appealing for its power to activate a desired C−H bond in the substrate leading to its selective functionalization. Reported here is the first photoredox‐mediated hydrogen‐atom transfer method for the efficient synthesis of ynones, ynamides, and ynoates with high regio‐ and chemoselectivity by direct functionalization of C (O)−H
Visible‐light‐induced photocatalytic decarboxylativealkynylations of carboxylicacids have been developed for the first time. The reaction features extremely mild conditions, broad substrate scope, and avoids additional oxidants. Importantly, a decarboxylative carbonylative alkynylation has also been carried out in the presence of carbon monoxide (CO) under photocatalytic conditions, which affords
Dimethyl Sulfoxide as an Oxygen Atom Source Enabled Tandem Conversion of 2‐Alkynyl Carbonyls to 1,2‐Dicarbonyls
作者:Yuan Lu、Mu‐Jia Luo、Ming Hu、Yang Li、Jin‐Heng Li
DOI:10.1002/adsc.202000066
日期:2020.4.27
compounds by means of a CuBr2/I2/DMSO/water system is developed, enabling the fromation of various functionalized 1,2‐dicarbonyl compounds, including 1,2‐diketones, α‐keto amides and α‐keto ester. This Cu‐promoted iodine‐mediated tandem procedure employs DMSO as the oxygen atom source of the formed carbonyl group through iodonium ion formation, nucleophilic DMSO addition and C−C bond cleavage cascades.
开发了通过CuBr 2 / I 2 / DMSO /水系统串联2-炔基羰基化合物的方法,使各种官能化的1,2-二羰基化合物(包括1,2-二酮,α-酮酰胺)形成和α-酮酸酯 此铜促进的碘介导的串联过程使用DMSO作为碘原子离子形成,亲核DMSO加成和CC键断裂级联反应形成的羰基的氧原子源。
Facile access to 1,3-diketones by gold(<scp>i</scp>)-catalyzed regioselective hydration of ynones
A facile and efficient synthesis of 1,3-diketones was developed by the gold(I)-catalyzed regioselective hydration of ynones at room temperature. This methodology employed 2.5 mol% of PPh3AuCl and 3 mol% of AgOTf as a simple catalytic system without any special phosphine ligand and was compatible with a wide range of substrates, giving rise to 1,3-diaryl, 1-alkyl-3-aryl-, and 1,3-dialkyl-1,3-diketones