Compounds > lithium-bis(trimethylsilyl)amide

lithium-bis(trimethylsilyl)amide and triethylamine

lithium-bis(trimethylsilyl)amide has been researched along with triethylamine* in 2 studies

Other Studies

2 other study(ies) available for lithium-bis(trimethylsilyl)amide and triethylamine

Article	Year
Lithium hexamethyldisilazide-mediated enolizations: influence of triethylamine on E/Z selectivities and enolate reactivities. Journal of the American Chemical Society, 2008, Jul-09, Volume: 130, Issue:27 Lithium hexamethyldisilazide (LiHMDS) in triethylamine (Et 3N)/toluene is shown to enolize acyclic ketones and esters rapidly and with high E/ Z selectivity. Mechanistic studies reveal a dimer-based mechanism consistent with previous studies of LiHMDS/Et 3N. E/ Z equilibration occurs when <2.0 equiv of LiHMDS are used. Studies of the aldol condensation and Ireland-Claisen rearrangement of the resulting Et 3N-solvated enolates show higher and often complementary diastereoselectivities when compared with analogous reactions in THF. The Et 3N-solvated enolates also display a marked (20-fold) acceleration of the Ireland-Claisen rearrangement with evidence of autocatalysis. A possible importance of amine-solvated enolates is discussed. Topics: Catalysis; Dimerization; Ethylamines; Furans; Ketones; Lithium Compounds; Silanes; Stereoisomerism	2008
Lithium hexamethyldisilazide/triethylamine-mediated ketone enolization: remarkable rate accelerations stemming from a dimer-based mechanism. Journal of the American Chemical Society, 2003, Apr-09, Volume: 125, Issue:14 Mechanistic studies of the enolization of 2-methylcyclohexanone mediated by lithium hexamethyldisilazide (LiHMDS; TMS2NLi) in toluene and toluene/triethylamine (Et3N) mixtures are described. Structural studies of LiHMDS/ketone mixtures in toluene reveal cyclic dimer (TMS2NLi)2(ketone). Rate studies using in situ IR spectroscopy show the enolization proceeds via a dimer-based transition structure, [(TMS2NLi)2(ketone)]. NMR spectroscopic studies of LiHMDS/ketone mixtures in the presence of relatively unhindered trialkylamines such as Me2NEt reveal the quantitative formation of cyclic dimers of general structure (TMS2NLi)2(Et3N)(ketone). Rate studies trace a >3000-fold rate acceleration to a dimer-based transition structure, [(TMS2NLi)2(Et3N)(ketone)]. Topics: Dimerization; Ethylamines; Ketones; Lithium Compounds; Silanes	2003

Article

Year

Lithium hexamethyldisilazide-mediated enolizations: influence of triethylamine on E/Z selectivities and enolate reactivities.

Journal of the American Chemical Society, 2008, Jul-09, Volume: 130, Issue:27

Lithium hexamethyldisilazide (LiHMDS) in triethylamine (Et 3N)/toluene is shown to enolize acyclic ketones and esters rapidly and with high E/ Z selectivity. Mechanistic studies reveal a dimer-based mechanism consistent with previous studies of LiHMDS/Et 3N. E/ Z equilibration occurs when <2.0 equiv of LiHMDS are used. Studies of the aldol condensation and Ireland-Claisen rearrangement of the resulting Et 3N-solvated enolates show higher and often complementary diastereoselectivities when compared with analogous reactions in THF. The Et 3N-solvated enolates also display a marked (20-fold) acceleration of the Ireland-Claisen rearrangement with evidence of autocatalysis. A possible importance of amine-solvated enolates is discussed.

Topics: Catalysis; Dimerization; Ethylamines; Furans; Ketones; Lithium Compounds; Silanes; Stereoisomerism

2008

Lithium hexamethyldisilazide/triethylamine-mediated ketone enolization: remarkable rate accelerations stemming from a dimer-based mechanism.

Journal of the American Chemical Society, 2003, Apr-09, Volume: 125, Issue:14

Mechanistic studies of the enolization of 2-methylcyclohexanone mediated by lithium hexamethyldisilazide (LiHMDS; TMS2NLi) in toluene and toluene/triethylamine (Et3N) mixtures are described. Structural studies of LiHMDS/ketone mixtures in toluene reveal cyclic dimer (TMS2NLi)2(ketone). Rate studies using in situ IR spectroscopy show the enolization proceeds via a dimer-based transition structure, [(TMS2NLi)2(ketone)]. NMR spectroscopic studies of LiHMDS/ketone mixtures in the presence of relatively unhindered trialkylamines such as Me2NEt reveal the quantitative formation of cyclic dimers of general structure (TMS2NLi)2(Et3N)(ketone). Rate studies trace a >3000-fold rate acceleration to a dimer-based transition structure, [(TMS2NLi)2(Et3N)(ketone)].

Topics: Dimerization; Ethylamines; Ketones; Lithium Compounds; Silanes

2003