Preparation of Mesoporous SBA-16 Silica-Supported Biscinchona Alkaloid Ligand for the Asymmetric Dihydroxylation of Olefins

Table 2

Heterogeneous AD of olefins using SBA-16-supported Ligand 1 ^a.

Entry	Olefin	Time (h)	Yield (%)	(%) Ee^b	Config.^b
1		7	93	>99	S, S
2^c		7	91	98	S, S
3^d		8	90	97	S, S
4		9	91	96	2R, 3S
5		10	92	94	2S, 3S
6		15	92	92	S

aThe reactions were carried out at RT; molar ratio of olefin/OsO₄/supported ligand = 1/0.01/0.01. ^bEe and absolute configuration were determined by chiral GC analysis. ^cMolar ratio of olefin/OsO₄/supported ligand = 1/0.005/0.005. ^dReaction was carried out with regenerated 1 without further addition of OsO₄.