Progress towards the Stereoselective Synthesis of 3,6-Disubstituted 1,2-Diamino-4-cyclohexenes by Ring Closing Metathesis Reaction
作者:Stefano Grilli、Gianluca Martelli、Diego Savoia、Carla Zazzetta
DOI:10.1002/1615-4169(200212)344:10<1068::aid-adsc1068>3.0.co;2-s
日期:2002.12
The ring closing metathesis of 4(R),5(R)-bis[1(S)-phenylethylamino]-3,6-diethenyl-1,7-octadiene required the preliminary formation of the cyclic formaldehyde aminal, then the use of the Grubbs, ruthenium benzylidene complex (10 mol %) in refluxing toluene in the presence of 2 equivalents of trifluoroacetic acid. The cyclic aminal was cleaved in situ after the cyclisation step, so that the final product was the 1,2-diamino-3,6-diethenylcyclohex-4-ene derivative. The predominant C-1-symmetric diastereomer was isolated with 48% yield.