1422427-30-2Relevant academic research and scientific papers
Unusual regioselectivity in the aldehyde addition reactions of allenyl/propargyl zirconium complexes derived from γ-(2-Pyridyl)propargyl ethers: Synthesis of multisubstituted α-hydroxyallenes
Fan, Guoqin,Xie, Xin,Liu, Yuanhong,Li, Yuxue
, p. 1636 - 1642 (2013/05/08)
Zirconium-mediated reactions of γ-(2-pyridyl)propargyl ethers with aldehydes afford α-hydroxyallenes selectively via the formation of allenyl/propargyl zirconium species. The reaction outcome is quite different to that of the reactions using propargylic ethers without a pyridyl group reported so far, in which homopropargyl alcohols were formed predominantly. The structure of allenylzirconium intermediate has been confirmed by X-ray crystal analysis which reveals an intramolecular Zr-N coordination. DFT calculations suggest that the smaller steric effect of the pyridine ring compared with the phenyl ring and its capability to form hydrogen bondings with hydrogen atoms of the Cp ligand and the aldehyde may account for the observed regioselectivity.
