90977-74-5Relevant academic research and scientific papers
CH3Li/TiCl4: A NON-BASIC AND HIGHLY SELECTIVE GRIGNARD ANALOGUE
Reetz, M. T.,Kyung, S. H.,Huellmann, M.
, p. 2931 - 2935 (2007/10/02)
Treatment of CH3Li or CH3MgCl with TiCl4 results in quantitative formation of CH3TiCl3, a non-basic reagent which reacts chemo- and stereoselectively with carbonyl compounds.It is considerably more reactive than the alkoxy analogue CH3Ti(OCHMe2)3.This means that selective addition to ketones in the presence of such a functionality as nitro, cyano and ester groups is possible.Addition to enolizable ketones is smooth.The stereoselectivity is comparable to that observed for CH3Ti(OCHMe)3.
Chemoselective Addition of Organotitanium Reagents to Carbonyl Compounds
Reetz, Manfred T.,Westermann, Juergen,Steinbach, Rainer,Wenderoth, Bernd,Peter, Roland,et al.
, p. 1421 - 1440 (2007/10/02)
The conversion of classical carbanions such as RMgX, RLi, or deprotonated nitriles, sulfones, and carboxylic esters into titanium analogs results in reagents which add chemoselectively to carbonyl compounds in the presence of other functional groups.The standard titanating agent is chlorotriisopropoxytitanium (1).Grignard-type reactions and aldol additions are aldehyde-selective in the presence of ketones.Other functional groups such as alkyl and aryl halides, esters, amides as well as nitro and cyano moieties are tolerated.Discrimination between two aldehydes or two ketones is also possible.Replacing alkoxy ligands by methyl groups at titanium increases reactivity dramatically, relative rates increasing in the series CH3Ti(OCHMe2)3 (CH3)2Ti(OCHMe2)2 (CH3)4Ti.The latter reagent and its zirconium analog methylate sterically hindered and/or enolizable ketones which normally fail to undergo Grignard reactions.The ate complex H2C=CHCH2Ti(OCHMe2)4MgCl (63) is aldehyde-selective, while the amino analog H2C=CHCH2Ti(NMe2)4MgCl (64) adds selectively to ketones in the presence of aldehydes.
