In Situ Generated Ag^II-Catalyzed Selective Oxo-Esterification of Alkyne with Alcohol to α-Ketoester: Photophysical Study

Abstract

An expert and easy one-step catalytic method for the multi O-C coupling of alkyne is developed for the synthesis of valuable α-ketoesters and their chiral analogues, in contrast to the generation of esters by a noncatalytic method. The in situ generated powerful Ag(II) catalyst from AgOTf is the workhorse in the oxidative grafting of alkyne with PhIO and alcohol. The radical mechanism is confirmed in our controlled experiments and UV-vis study.

CuBr–ZnI2 Combo-Catalysis for Mild CuI–CuIII Switching and sp2 C–H Activated Rapid Cyclization to Quinolines and Their Sugar-Based Chiral Analogues: A UV–Vis and XPS Study

“…However, ZnI 2 was our cocatalyst of choice because of its low cost and easy availability. The reaction with the nonmetallic Lewis acid cum oxidant PhIO − was unsuccessful because of the complexation and/or oxidation of the aromatic amine ( 1a , entry 27). The reaction was completely blocked in an N 2 atmosphere, which confirmed the need for aerial oxygen in the construction of quinolines ( 4a , entry 28).…”

Recent Advances in Iodosobenzene‐Mediated Construction of Heterocyclic Scaffolds: Transition‐Metal‐Free Approaches and Scope

“…Synthetic organic chemists are involved in a continuous effort to reveal the excellent Lewis acidic oxidizing characteristics of these reagents from the last decade of the 20 th century to recent years. These reagents led to rapid development in the modern field of C–C/C–X (X = O, N, halogens) coupling and cyclization reactions . Some chiral hypervalent iodine reagents were also in the limelight for asymmetric synthesis .…”

Palladium-Catalyzed Direct α-Ketoesterification of 8-Methylquinoline Derivatives with α-Ketoacids via Dehydrogenation Coupling Reaction

“…13 During the same year, Maiti reported the Ag-catalyzed oxo-esterification of alkyne with alcohol to α-ketoester. 14 With the development of synthetic methodology, the cross dehydrogenative coupling reaction has attracted much attention because of the direct construction of C−C 15 and C−X 16 bonds. Thus, although various strategies have been developed for the preparation of α-ketoesters, [11][12][13][14]17 the direct α-ketoesterification via dehydrogenation coupling reaction is still extensively desirable due to the use of simple reactants, shorter reaction steps, and reduced amounts of waste products.…”

“…Recently, Song developed the Sakurai allylation of β,γ -unsaturated ketoesters with silicon-substituted enol ester to achieve the α-ketoesters . During the same year, Maiti reported the Ag-catalyzed oxo-esterification of alkyne with alcohol to α-ketoester …”

“…With the development of synthetic methodology, the cross dehydrogenative coupling reaction has attracted much attention because of the direct construction of C–C and C–X bonds. Thus, although various strategies have been developed for the preparation of α-ketoesters, − , the direct α-ketoesterification via dehydrogenation coupling reaction is still extensively desirable due to the use of simple reactants, shorter reaction steps, and reduced amounts of waste products. However, there have been few reports of α-ketoesterification reaction via direct dehydrogenation coupling of alkyl-substituted aromatics with glyoxylic acid derivatives.…”