On the Mechanisms of Enantioselective Reactions Using ?,?,??,?? -Tetraaryl-1,3-dioxolane-4,5-dimethanol(TADDOL)-Derived Titanates: Differences betweenC2- andC1-symmetrical TADDOLs - facts, implications and generalizations
作者:Dieter Seebach、Dietmar A. Plattner、Albert K. Beck、Yan Ming Wang、Daniel Hunziker、Walter Petter
DOI:10.1002/hlca.19920750704
日期:1992.11.11
titanate is involved in the product-forming step, (ii) that the bulky TADDOLate ligand renders the Ti-center catalytically more active than that of (i-PrO)4Ti, due to fast dynamics of ligand exchange on the sterically hindered Ti-center (Table 5, Fig. 3), and (iii) that the role of excess (i-PrO)4Ti is to remove – by ligand exchange – the product alkoxides (R*O) from the catalytically active Ti-center