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Reaction of N‐Heterocyclic Silylenes with Thioketone: Formation of Silicon–Sulfur Three (S i‐C‐S )‐ and Five (S i‐C‐C‐C‐S )‐Membered Ring Systems
Author(s) -
Azhakar Ramachandran,
Ghadwal Rajendra S.,
Roesky Herbert W.,
Mata Ricardo A.,
Wolf Hilke,
HerbstIrmer Regine,
Stalke Dietmar
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201203242
Subject(s) - sulfur , ring (chemistry) , silicon , chemistry , organic chemistry
Three‐ and five‐membered rings that bear the (S i‐C‐S ) and (S i‐C‐C‐C‐S ) unit have been synthesized by the reactions of L SiCl ( 1 ; L =PhC(N t Bu) 2 ) and L′ Si ( 2 ; L′ =CH{(CCH 2 )(CMe)(2,6‐ i Pr 2 C 6 H 3 N) 2 }) with the thioketone 4,4′‐bis(dimethylamino)thiobenzophenone. Treatment of 4,4′‐bis(dimethylamino)thiobenzophenone with L SiCl at room temperature furnished the [1+2]‐cycloaddition product silathiacyclopropane 3 . However, reaction of 4,4′‐bis(dimethylamino)thiobenzophenone with L′ Si at low temperature afforded a [1+4]‐cycloaddition to yield the five‐membered ring product 4 . Compounds 3 and 4 were characterized by NMR spectroscopy, EIMS, and elemental analysis. The molecular structures of 3 and 4 were unambiguously established by single‐crystal X‐ray structural analysis. The room‐temperature reaction of 4,4′‐bis(dimethylamino)thiobenzophenone with L′ Si resulted in products 4 and 5 , in which 4 is the dearomatized product and 5 is formed under the 1,3‐migration of a hydrogen atom from the aromatic phenyl ring to the carbon atom of the CS unit. Furthermore, the optimized structures of probable products were investigated by using DFT calculations.