Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA.
J Am Chem Soc. 2010 Feb 17;132(6):1760-1. doi: 10.1021/ja9097675.
Enantioselective transfer hydrogenation of gem-dibenzoate 1e in the presence of aromatic, alpha,beta-unsaturated, or aliphatic aldehydes 2a-i mediated by isopropyl alcohol and employing a cyclometalated iridium C,O-benzoate derived from allyl acetate, 4-cyano-3-nitrobenzoic acid, and (R)-SEGPHOS delivers products of alkoxyallylation 3a-i, 4a, 4e, 4f, and 4i in good isolated yields (62-82%) with good to excellent diastereoselectivities (7:1 to 18:1 dr) and exceptional enantioselectivities (90-99% ee). This protocol provides an alternative to the use of premetalated nucleophiles in carbonyl alkoxyallylation.
在异丙醇的存在下,用乙酸烯丙酯、4-氰基-3-硝基苯甲酸和(R)-SEGPHOS 衍生的环金属化铱 C,O-苯甲酸酯对 1e 进行对映选择性转移氢化,可对芳香族、α,β-不饱和或脂肪族醛 2a-i 进行催化,得到烷氧基烯丙基化产物 3a-i、4a、4e、4f 和 4i,产率良好(62-82%),非对映选择性优异(7:1 至 18:1 dr),对映选择性极好(90-99%ee)。该方案为羰基烷氧基烯丙基化中使用预金属化亲核试剂提供了一种替代方法。