Search

The synthesis of hybrid “metalloporphyrin-ellipticine” molecules is reported. These molecules are based on 9-methoxyellipticine and [5-(4-hydroxyphenyl)-10,15,20-tris (4-tolyl)]porphyrin linked by a ten-bond chain, −(CH2)4-CO-NH-(CH2)3−, between the hydroxyl group of the porphyrin and the pyridine nitrogen of the pyrido-carbazole. These molecules have been metallated with manganese, iron or zinc salts.

The reaction of α-branched aldehydes with diethyl 1-carbomethoxyethyl phosphonate 1b in THF/nBuLi at low temperature leads stereoselectively to Z α-methyl α,β-unsaturated esters. From a linear aldehyde, the reaction is less stereoselective, while from α,β-unsaturated ones, the E isomers are predominantly formed in good yields. From diphenyl 1-carbomethoxyethyl phosphine oxide 2b, E α-methyl α,β-unsaturated esters are stereoselectively formed either in DMF/tBuOK or in phase transfer conditions, whatever the starting aldehyde is, also in good yields. This reagent can thus advantageously replace the corresponding P-ylid. In all cases, the reaction conditions are determined so that by-products formation is minimized.

Diphosphiranes 3a - 3f are obtained by action of diazo derivatives and carbenes on the trans-diphosphene 1 . The structures are elucidated by spectroscopic methods. In all cases the cycloaddition reaction is stereoselective.