. Author manuscript; available in PMC: 2010 Dec 30.

Published in final edited form as: J Am Chem Soc. 2009 Dec 30;131(51):18343–18357. doi: 10.1021/ja9053948

Table 6.

Selected Optimization Studies for DAAA of Tri-substituted Enol Carbonates.^a



entry	T °C	solvent	ee^b	45	46	47
1	23	PhMe	95%	(62)^c	(29) ^c	9%
2	4	PhMe	95%	53(52)^c	36(39)^c	8%
3	23	THF	94%	51(51)^c	25(35)^c	5%
4	50	THF	89%	46(44)^c	13(20)^c	19%
5^d	50	THF	89%	22(18)^c	7(10)^c	38%
6	23	dioxane	97%	81(81)^c	6	<2%

All reactions were performed on a 0.3 mmol scale at 0.1 M for 20 h at 23 °C using 2.5 mol% 20 and 5.5 mol% (R,R)-L4; yields were measured by quantitative GC analysis using decane as internal reference.

Ee values were determined by chiral HPLC.

Isloated yields.

1.0 mol% 20 and 5.0 mol% (R,R)-L4 were used.