Chemistry and Biochemistry
Bayer School of Natural and Environmental Sciences
Transmissive olefination, [3, 3] Rearrangement, Alkenenitriles, Grignard reagents, Allylic or allenic halides, Niobium halides
Part 1. Grignard reagents readily add to alkenenitriles bearing an adjacent hydroxyl group to afford Z-alkenenitriles with transmissive relocation of the C=C bond. Mechanistically the transmissive olefination is consistent with rearrangement through a cyclic 6-membered transition structure in which the formal displacement of hydroxide occurs by forming magnesium oxide.
Part 2. Addition of niobium halides to a series of allylic or propargylic alkoxides directly provides allylic or allenic halides. Halogenation formally occurs through a metalla-halo-[3, 3] rearrangement although at least these different mechanisms may operate competitively. Transposition of the olefin is equally effective for allylic alkoxides prepared by necleophilic addition, deprotonation, or reduction.
Yao, L. (2011). Transmissive Olefination of Alkenenitrile and Allylic Halides (Master's thesis, Duquesne University). Retrieved from https://dsc.duq.edu/etd/1387