First examples of the synthesis of macroaluminahetero(N,S)cycles with the participation of metallo(Ti,Zr)cene catalysts

Mechanism of Cp2ZrCl2-Catalyzed Olefin Cycloalumination with AlEt3: Quantum Chemical Approach

“…For example, the aluminum atom in fivemembered metallacarbocycles can be replaced by boron or phosphorus upon treatment of alumolanes with boron halides or dichlorophosphines to give 1-halo-3-substituted borolanes 8,35 and 1,3-disubstituted phospholanes, 7a respectively. Moreover, the first one-pot method for the synthesis of macroaluminahetero(N,S)cycles, as applied to 4-aryl-2,6,8,11tetraethyl-1,7-dithia-4-aza-2,6,8,11-tetraaluminacycloundecanes from 3-aryl-1,5,3-dithiazepanes, catalyzed by Cp 2 TiCl 2 and Cp 2 ZrCl 2 , 36 is also based on transmetalation of titanoceneheterocycles by EtAlCl 2 , formed in situ upon known insertion reaction of titanocene Cp 2 Ti into the C−S bond. 37 By the beginning of our studies, no data on the mechanism of the Zr → Al transmetalation reaction for five-membered rings were present in the literature.…”