| 摘要 |
<p>This invention relates to processes and intermediates for the stereoselective alkylation of carbonyl groups. The invention in particular allows the stereoselective preparation of the antidepressant drug escitalopram. It has been found that boric or boronic acid derivatives are useful bridging elements for the attachment of a chiral group to a compound containing a carbonyl group to be alkylated. The said borates and boronates are thus useful in a process for the asymmetric alkylation of a carbonyl group in a compound containing a carbonyl group and an anchor group capable of reacting with a boric or boronic acid derivative. The asymmetric alkylation can be carried out by admixing the compound containing a carbonyl group to be alkylated and the anchor group capable of reacting with a boric or boronic acid derivative with a boric or boronic acid derivative, adding a chiral alcohol, and adding an organometallic compound. After the alkylation reaction, the borate and boronate can be easily removed by hydrolysis.</p> |
