... Catalysis Letters. March 2014 , Volume 144, Issue 3, pp 419-433. ... The yield and enantioselectivity results showed that organic base N,N,N′,N′-tetramethylethylenediamine (TMEDA) and 1,2,2,6,6-pentamethylpiperidine (PMP) were both no better than triethylamine and no ...