Catching Elusive 2‐Furyl Carbenes with Silanes: A Metal‐Free Microwave‐Assisted Silicon‐Hydrogen Bond Functionalization

Abstract

An efficient, metal‐free, silicon–hydrogen bond functionalization based on the microwave‐assisted reaction of readily available enynones and silanes is reported. This process seemingly proceeds through a 2‐furyl carbene species, a particularly elusive intermediate. Preliminary studies on the metal‐free oxygen–hydrogen and nitrogen–hydrogen bond functionalization of representative alcohols, azoles and sulfonamides are also provided.magnified image

Rhodium-Catalyzed Si–H Bond Insertion Reactions Using Functionalized Alkynes as Carbene Precursors

“…Although there have been several reports of Si–H bond insertion reactions using alkynes as carbene precursors, the enantioselective version of this reaction remains unknown to the best of our knowledge. Herein, we report a highly enantioselective rhodium-catalyzed Si–H bond insertion reaction that uses alkynes as carbene precursors.…”

Metal-Free Insertion Reactions of Silanes with Aryldiazoacetates

“…The construction of C–Si bonds is an important transformation in the synthesis of organosilicon compounds. In this context, the insertion reaction of carbenes into the Si–H bond of silanes is very attractive (Scheme a). , It was initially described in 1988 and constitutes a straightforward reaction for the atom-efficient construction of new C–Si bonds. − Today, different approaches to this transformation have been realized using precious metal complexes based on rhodium, iridium, or ruthenium and even highly enantioselective Si–H insertion reactions have been described. More lately, carbene transfer catalysts based on first row transition metal complexes found application in this reaction, though typically high catalyst loadings need to be applied. , In this context, iron plays an important role and directed evolution has recently led to the development of important enantioselective Si–H insertion reactions by enzymatic carbene transfer .…”

Synthesis of Multisubstituted Furans via a Catalyst- and Additive-Free Tandem Reaction of Enynones with Sulfinic Acids in Water

“…Finally, intermediate E abstracted a hydrogen atom from H 2 O and 2a to afford desired product 3aa . On the basis of the results of Scheme b and d, the desired product 3aa might be formed in the presence of N 2 through another reaction pathway, which might be achieved by a cooperative effect between the carbonyl group of 1a and 2a via a hydrogen bond. …”