Generation of Allylmagnesium Reagents by Hydromagnesiation of 2‐Aryl‐1,3‐dienes

Abstract

A protocol for the generation of allylmagnesium reagents from 2‐aryl‐1,3‐dienes was developed using magnesium hydride (MgH2) that is generated in situ by solvothermal treatment of sodium hydride (NaH) and magnesium iodide (MgI2) in tetrahydrofuran (THF). Downstream functionalization of the resulting allylmagnesium reagents with carbonyl compounds or alkyl (pseudo)halides delivers branched products having an allylic quaternary carbon center, whereas that with chlorosilanes resulted in formation of linear allylsilanes in regio and stereoselective manners. Further derivatizations of the homoallylic alcohols and allylsilanes were also demonstrated.

Organophosphates as Versatile Substrates in Organic Synthesis

“…In contrast, phosphate with a trimethylsilyl group tends to undergo isomerization at the double bond, resulting in Z -diene 4 – 2g . The simplicity and effectiveness of this methodology are further underscored by its widespread adoption in numerous publications [ 47 , 48 , 49 , 50 , 51 , 52 , 53 ].…”

Hydroalkylation of 1,1‐Diarylalkenes Mediated by Magnesium Hydride in Ethereal Solvents

“…As a distinct mode of approach, the hydromagnesiation of carbon‐carbon unsaturated bonds could potentially offer an atom‐economical way toward organomagnesium reagents [11] . In this context, our group has recently reported that the solvothermal treatment of magnesium iodide (MgI 2 ) with sodium hydride (NaH) in THF induces counter ion metathesis to form reactive magnesium hydride (MgH 2 ), which facilitates the hydromagnesiation of arylalkynes, [12] 1,3‐enynes, [13,14] and 2‐aryl‐1,3‐dienes, [15] affording alkenylmagnesium, allenyl/propargylmagnesium and allylmagnesium species, respectively ( Scheme 1 a ). The resulting organomagnesium complexes could be functionalized with various electrophiles, enhancing molecular complexities starting from readily available and simple starting materials.…”