Reversible, Complete Cleavage of SiSi Double Bonds by Isocyanide Insertion

Abstract

There and back: An isocyanide‐centered silene–disilene reversibility was observed for the insertion of isocyanides into unsymmetrically substituted disilenes. This reaction leads to the formation of silenes at room temperature; the disilene is regenerated in the presence of a Lewis acid.

Activation of boryl-, borylene and metalloborylene complexes by isonitriles

“…Upon treatment of 2 with B(C 6 F 5 ) 3 , full conversion to compound 1 and the Lewis acid-base pair (C 6 F 5 ) 3 B-CNtBu was observed by NMR. 34 As shown in Scheme 1A, the addition of Mes*NC to the manganese borylene complex [(Z 5 -C 5 H 5 )(OC) 2 MnBtBu] induced ligand coupling. S1, ESI ‡) showed a shallow potential energy surface with an intermediate, wherein the isonitrile bridges the B-Fe bond, that is only +4.1 kcal mol À1 above the starting materials, and the final structure (2) is just À1.2 kcal mol À1 below the starting materials (DG 298.15 ; B3LYP/6-311+G(d,p)).…”

σ–π Conjugated Organosilicon Hybrid Polymers from Copolymerization of a Tetrasiladiene and 1,4‐Diethynylbenzene

“…Herein, we report an atom‐economic, catalyst‐ and essentially by‐product‐free protocol for the synthesis of σ–π conjugated organosilicon polymers under mild reaction conditions taking advantage of the two highly reactive SiSi units in a stable para ‐phenylene‐bridged tetrasiladiene 17. In our recent report on its reactivity towards isonitriles, we proposed the possible use of this tetrasiladiene as a polymerization precursor 18. Herein, we employ the regiospecific [2+2] cycloaddition of alkynyl moieties to SiSi double bonds for the synthesis of a σ–π conjugated organosilicon hybrid polymer.…”

Functional Disilenes in Synthesis

“…The molecular structure of 133 reveals the polarization of the Si=C bond in form of a pyramidalized environment of the three‐coordinate silicon atom (sum of angles: 353.05°). The reactions of disilene 134 with isocyanides leads via the disilacyclopropanimines 135 a – c as likely intermediates (detected by NMR at low temperature) to the silaaziridines 136 a – c . The process of complete cleavage of the Si=Si double bond in 134 to form 136 a – c is insofar reversible that 134 is reformed almost quantitatively upon addition of large excess of BEt 3 as isocyanide scavenger (Scheme ).…”