Intramolecular Sila-Matteson Rearrangement: A General Access to Silylated Heterocycles

Abstract

A series of new silylated heterocycles has been efficiently prepared using an intramolecular silicon version of the Matteson rearrangement, providing two isomers of binuclear heterocycles. This method applies to a large variety of substrates, a direct relationship between the Hammett constants of the aromatic substituents and the isomer ratio being observed. Complementary experiments suggest that a common pentaorganosilicate species is involved.

Anionic Access to Silylated and Germylated Binuclear Heterocycles

“…[17] When it comes to the 4-aminopyridine derivatives 8 and 34, this effect is not observed anymore, probably because the prime electron-deficient character of the pyridine moiety drives the rearrangement toward the a isomer, as noted before with other electron-withdrawing phenyl substituents. [14] Note that the results in entries 7 and 8 (Table 2) demonstrate that the sila-Matteson rearrangement applies equally well to pyridinic substrates, extending substantially its interest in heterocyclic chemistry.…”

“…[14] Note that the construction of a [3.4.0] silylated bicyclic skeleton is also possible by this route, as demonstrated in the case of thiophene 7 (entry 7, Table 1). …”

“…The electronic character of the fused aromatic ring was shown to govern the ratio between the regioisomers and a mechanism involving a pentaorganosilicate species was evidenced (Scheme 1). [14] This preliminary study was conducted on dimethyl-substituted silicon tethers borne by several phenol and aniline derivatives. We describe in this paper the generalization of this chemistry to a series of new silylated substrates, as well as its extension toward the germylated ones.…”

Synthesis, Reactivity, Functionalization, and ADMET Properties of Silicon-Containing Nitrogen Heterocycles

“…19 Therefore, a more direct approach was sought (Scheme 8). Lateral lithiation of Bocprotected 2-toluidine afforded a dilithium intermediate that was trapped with 2 equiv of the (chloromethyl)dimethylsilyl chloride to afford 42 .…”

The first intramolecular silene Diels–Alder reactions

“…The challenge for the continued development of these reagents is that there are relatively limited methods for the preparation of functionalised silanes, particularly when the silicon centre is contained within a ring structure. 3 One option that remains largely unexplored is the application of lowcoordinate silicon compounds. Such compounds, silenes (and disilenes), silynes and silylenes which represent the organosilicon equivalents of alkenes, alkynes and carbenes respectively, display a fascinating array of chemistry that has much to offer synthetic chemistry.…”