Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 20, 2013
Previous Article Next Article

Lanthanum(iii) catalysts for highly efficient and chemoselective transesterification

Author affiliations

Abstract

A facile, atom-economical, and chemoselective esterification is crucial in modern organic synthesis, particularly in the areas of pharmaceutical, polymer, and material science. However, a truly practical catalytic transesterification of carboxylic esters with various alcohols has not yet been well established, since, with many conventional catalysts, the substrates are limited to 1°- and cyclic 2°-alcohols. In sharp contrast, if we take advantage of the high catalytic activities of La(Oi-Pr)3, La(OTf)3, and La(NO3)3 as ligand-free catalysts, ligand-assisted or additive-enhanced lanthanum(III) catalysts can be highly effective acid–base combined catalysts in transesterification. A highly active dinuclear La(III) catalyst, which is prepared in situ from lanthanum(III) isopropoxide and 2-(2-methoxyethoxy)ethanol, is effective for the practical transesterification of methyl carboxylates, ethyl acetate, weakly reactive dimethyl carbonate, and much less-reactive methyl carbamates with 1°-, 2°-, and 3°-alcohols. As the second generation, nearly neutral “lanthanum(III) nitrate alkoxide”, namely La(OR)m(NO3)3−m, has been developed. This catalyst is prepared in situ from inexpensive, stable, low-toxic lanthanum(III) nitrate hydrate and methyltrioctylphosphonium methyl carbonate, and is highly useful in the non-epimerized transesterification of α-substituted chiral carboxylic esters, even under azeotropic reflux conditions. In these practical La(III)-catalyzed transesterifications, colorless esters can be obtained in small- to large-scale synthesis without the need for inconvenient work-up or careful purification procedures.

Graphical abstract: Lanthanum(iii) catalysts for highly efficient and chemoselective transesterification

Back to tab navigation

Article information


Submitted
14 Nov 2012
Accepted
14 Dec 2012
First published
17 Jan 2013

Chem. Commun., 2013,49, 1983-1997
Article type
Feature Article

Lanthanum(III) catalysts for highly efficient and chemoselective transesterification

M. Hatano and K. Ishihara, Chem. Commun., 2013, 49, 1983
DOI: 10.1039/C2CC38204K

Social activity

Search articles by author

Spotlight

Advertisements