Synthesis of a Dichlorosilaimine Coordinated by an N‐Heterocyclic Carbene from ArN(SiMe₃)SiHCl₂

Abstract

NHC-stabilized dichlorosilaimine ArN＝Si(IiPr)Cl 2 (2) (Ar＝2,6-iPr 2 C 6 H 3 , IiPr＝1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) and disilane LSiHCl-SiCl 2 L (L＝ArNSiMe 3 ) (3) could be synthesized from the reaction of aminodichlorosilane ArN(SiMe 3 )SiHCl 2 (1) with IiPr under different conditions. This represents the first route to the generation of donor-stabilized dichlorosilaimine from substituted chlorosilane in the presence of an NHC via dehydrosilylation.

NHCs in Main Group Chemistry

“…The first NHC-stabilized dichlorosilaimines 533a – c were synthesized by Roesky et al in 2010, and recently the pool of reported compounds was extended with the synthesis of the similar complex 534 by Cui and co-workers (Figure ). − The implementation of the sterically demanding triphenylsilyl group led to the isolation of the further silaimine NHC adduct 535 . The overall detected chemical shifts for the central silicon atoms range from δ = −75.3 to δ = −107.1 ppm.…”

“…All attempts to increase the yield by changing the reaction conditions only led to the formation of other products such as (I i Pr 2 Me 2 )­SiCl 4 ( 491c ), Dipp­(TMS)­NSiCl 3 , the silaimine dimer, etc. Recently, a novel dehydrosilylation approach for the synthesis of complex 534 has been reported . Treatment of the aminodichlorosilane Dipp­(TMS)­NSiHCl 2 with less than 2 equiv of I i Pr 2 Me 2 in THF yields the NHC-stabilized silaimine 534 in addition to the aminochlorosilylene 670 .…”

“…Recently, a novel dehydrosilylation approach for the synthesis of complex 534 has been reported. 571 Conversion of NHC adduct 670 with electron-deficient internal or terminal alkynes affords the variety of NHCcoordinated cis-1,2-bis-silylated alkenes 538 in an efficient and regiospecific manner. 575 In a similar fashion, several NHC-stabilized trans-1,2disilylimines 539 are accessible in a highly regioselective process by treating 670 with different aryl-substituted nitriles.…”