TY - JOUR

T1 - Multiply metallated organic intermediates: a tris(lithiomethyl)-cyclohexane and a hexalithiotrimethyl-cyclohexanetriolate.

AU - Rücker, Christoph

N1 - Funding Information: This work was supported by the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie, and BASF AG. The author thanks Prof. Dr. H. Fritz and Dr. D. Hunkler for the NMR spectra, Dr. J. Worth for MS measurements, and Dipl.-Math. G. Seiffert for mathematical advice.

PY - 1986/8/19

Y1 - 1986/8/19

N2 - Lithium di-t-butylbiphenyl (LiDBB) readily cleaves alkyl-sulphur bonds to yield long-lived organolithiums. Using this reagent trilithio species (2b) was obtained from tris-phenylthioether (1b). The organometallic intermediates (2b) and (5b) were characterised by their reactions with electrophiles (e.g. D2O, CO2, Me3Si-OTf, Me-OTf) to yield di- and hexasubstituted cyclohexanes (3) and (6). Prolonged treatment of the trilithoxy tris-phenylthioether (1c) with excess LiDBB followed by addition of D2O and aqueous work-up gave a methyl-deuterated trimethylcyclohexanetriol (D2.5-3aα) demonstrating that at least one penta- and one hexalithio intermediate are involved. The structure of the latter intermediate could not be established unambiguously, but the unsymmetrical 1,1-dilithiated species (22) is prefered over the symmetrical hexalithio species (2c) on the basis of extensive transmetallation observed at the tetra- or pentalithio stage ( as seen in the deuterated phenylthiomethylcyclohexanetriol (15) and the absence of compelling evidence for the symmetrical tri(deuteriomethyl)cyclohexanetriol (3aβ), as judged from the CH3, CH2D, and CHD2 ratios in the deuterated product (D2.5-3aα).

AB - Lithium di-t-butylbiphenyl (LiDBB) readily cleaves alkyl-sulphur bonds to yield long-lived organolithiums. Using this reagent trilithio species (2b) was obtained from tris-phenylthioether (1b). The organometallic intermediates (2b) and (5b) were characterised by their reactions with electrophiles (e.g. D2O, CO2, Me3Si-OTf, Me-OTf) to yield di- and hexasubstituted cyclohexanes (3) and (6). Prolonged treatment of the trilithoxy tris-phenylthioether (1c) with excess LiDBB followed by addition of D2O and aqueous work-up gave a methyl-deuterated trimethylcyclohexanetriol (D2.5-3aα) demonstrating that at least one penta- and one hexalithio intermediate are involved. The structure of the latter intermediate could not be established unambiguously, but the unsymmetrical 1,1-dilithiated species (22) is prefered over the symmetrical hexalithio species (2c) on the basis of extensive transmetallation observed at the tetra- or pentalithio stage ( as seen in the deuterated phenylthiomethylcyclohexanetriol (15) and the absence of compelling evidence for the symmetrical tri(deuteriomethyl)cyclohexanetriol (3aβ), as judged from the CH3, CH2D, and CHD2 ratios in the deuterated product (D2.5-3aα).

KW - Chemistry

UR - http://www.scopus.com/inward/record.url?scp=33749105163&partnerID=8YFLogxK

U2 - 10.1016/S0022-328X(00)99547-0

DO - 10.1016/S0022-328X(00)99547-0

M3 - Journal articles

VL - 310

SP - 135

EP - 150

JO - Journal of Organometallic Chemistry

JF - Journal of Organometallic Chemistry

SN - 0022-328X

IS - 2

ER -