Synthesis, Structure, and Reactivity of Binaphthyl Supported Dihydro[1,6]diazecines

A short approach to chiral diaza-olefines from protected 2,2'-diamino-1,1'-binaphthyl is presented. Cis- and trans-olefines can be selectively obtained by twofold N-allylation followed by RCM or by bridging a 2,2'-diamino-1,1'-binaphthyl precursor with trans-1,4-dibromo-2-butene. Deprotection afforded cis- and trans-dihydro[1,6]diazecines 1 in 58 and 64% overall yield. The reactivity of the but-2-ene-1,4-diyl fragment was investigated yielding corresponding epoxides, diols, and mono- and dibromo products. In several cases rearrangements and participation of the proximate N-Boc group was observed. In no case could allylic substitution be accomplished. From 13 compounds X-ray structure analyses could be obtained.