Lanthanum compounds transformation

For catalytic asymmetric aldol-type reactions, the transformation of the methylene compounds to a silyl enolate or a silyl ketene acetal was at one time necessary. Recently, the aldol reaction of aldehydes with non-modified ketones was realized by use of the lanthanum-Li3-trisf(/ )-bi-naphthoxidej catalyst 22 [18]. According to the proposed catalytic cycle, after abstraction of an a-proton from the ketone, the reaction between the lithium-enolate complex and the aldehyde... 

Lanthanum monochloride LaCl has been less studied. Xin and Klynning (1994) reported molecular constants obtained from analysis of the rotational structure of IR bands in the thermal emission spectrum of LaCl recorded on a high-resolution Fourier transform spectrophotometer. It is worth noting that, despite a rather strong emission spectrum of LaCl, Xin and Klynning (1994) failed to detect the absorption spectrum of this compound. In this context, these authors selected, with low confidence and, apparently by analogy with the conclusions of Schall et al. (1983), the... 

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