Asymmetric 1,3-Dipolar Cycloadditions of Nitrones and Methacrolein Catalyzed by Chiral Bis-Titanium Lewis Acid: A Dramatic Effect of <i>N</i>-Substituent on Nitrone
Highly stereoselective 1,3-dipolar cycloadditions of methacrolein and nitrones could be realized by the use of bis-titanium chiral Lewis acid catalyst. Key to the success is the introduction of bulky N-substituent on nitrone to attenuate the undesired Lewis acid-nitrone complexation.
6,6′-Substituent effect of BINOL in bis-titanium chiral Lewis acid catalyzed 1,3-dipolar cycloaddition of nitrones
作者:Takuya Hashimoto、Masato Omote、Keiji Maruoka
DOI:10.1039/b804987d
日期:——
By the accommodation of modified BINOLs as chiral ligands, enantioselectivities in the bis-titanium chiral Lewis acid catalyzed1,3-dipolarcycloaddition of N-diphenylmethyl nitrones and methacrolein could be improved.