Synthesis and study of an unprecedented 1-hydro-1-lithio-1-silafluorene anion

Abstract

The 1-hydro-1-lithio-silafluorene anion 2 has been isolated and characterized by single-crystal X-ray analysis for the first time. Three tetrahydrofuran molecules coordinate with lithium atoms in the crystal structure of 2. 2 was reacted with a number of electrophilic reagents and it can be used as a useful reagent for generating various functional hydrogen-substituted silafluorenes. Treatment of 2 with 2 equiv. of chlorobis(isopropyl)phosphine afforded chloro-substituted silafluorene 4. The reaction of 8 which has a SiH-SiBr fragment with IiPrMe (IiPr: 2,5-diisopropyl-3,4-dimethylimidazol-1-ylidene) led to the formation of an Si-Si bond cleavage product, NHC-stabilized silacyclopentadienylidene 9.

Early Lanthanide(III) Ate Complexes Featuring Ln–Si Bonds (Ln = La, Ce): Synthesis, Structural Characterization, and Bonding Analysis

“…Alkali metal silanides have been reported to be widely used in preparations of metal silyl complexes. − [Si­(H)­Mes 2 ] − , [Si­(CH 3 )­Ph 2 ] − , and [SiPh 3 ] − silanides were synthesized from silyl chlorides via a slightly modified procedure previously reported by Tilley . Distinct from the relatively feasible synthesis of [Si­(H)­Mes 2 ] − , attempts for the synthesis of the less bulky [SiHPh 2 ] − based on this procedure were unsuccessful, and with the addition of an excess amount of 12-crown-4, the disilanide [Si­(Ph) 2 Si­(H)­Ph 2 ] − was obtained in a moderate yield (Scheme ).…”

NHCs in Main Group Chemistry

“…Cui et al used the silafluorene derivative 678 as a starting material for a NHC-mediated dehydrochlorination reaction with the intention to synthesize a novel disilene . Nevertheless, the reaction of 678 with I i Pr 2 Me 2 results in the cleavage of the Si–Si single bond under formation of the NHC-stabilized 1-silacyclopentadienylidene 679 (Scheme ).…”

“…Cui et al used the silafluorene derivative 678 as a starting material for a NHC-mediated dehydrochlorination reaction with the intention to synthesize a novel disilene. 663 Nevertheless, the reaction of 678 with I i Pr 2 Me 2 results in the cleavage of the Si−Si single bond under formation of the NHC-stabilized 1-silacyclopentadienylidene 679 (Scheme 116). The observed resonance for the Si(II) nucleus in the 29 Si NMR spectrum at δ = −33.0 ppm is close to those of the related complexes 645 and 675 (δ = −43.6 to −69.6 ppm), nonetheless considering the differences in the ligand framework.…”

Three-membered cyclic digermylenes stabilised by an N-heterocyclic carbene

“…During the reaction of K 2 [ 1a ] with dichlorogermylene 2 , the known NHC-stabilised silylene 6a was detected by NMR spectroscopy as a by-product and was identified by comparison with literature data. 47 After isolation of compound 5a , crystallization from diethyl ether allowed a second crop of a few dark red crystals of the tricyclic compound 8 that was identified by XRD analysis ( Scheme 1 ). When the reaction of K 2 [ 1a ] and dichlorogermylene 2 was followed by NMR spectroscopy, already at −30 °C a mixture of products was detected (see ESI † for details).…”