Wooten Alfred J, Kim Jeung Gon, Walsh Patrick J
P. Roy and Diana T. Vagelos Laboratories, University of Pennsylvania, Department of Chemistry, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, USA.
Org Lett. 2007 Feb 1;9(3):381-4. doi: 10.1021/ol062264h.
[reaction: see text] We report the catalytic asymmetric allylation of ketones under highly concentrated reaction conditions with a catalyst generated from titanium tetraisopropoxide and BINOL (1:2 ratio) in the presence of isopropanol. This catalyst promotes the addition of tetraallylstannane to a variety of ketones to produce tertiary homoallylic alcohols in excellent yield (80-99%) with high enantioselectivities (79-95%). The resulting homoallylic alcohols can also be epoxidized in situ using tert-butyl hydroperoxide (TBHP) to afford cyclic epoxy alcohols in high yield (84-87%).
[反应:见正文] 我们报道了在高浓度反应条件下,使用四异丙醇钛和联萘酚(1:2比例)在异丙醇存在下生成的催化剂,实现酮的催化不对称烯丙基化反应。该催化剂能促进四烯丙基锡向多种酮的加成反应,以优异的产率(80 - 99%)和高对映选择性(79 - 95%)生成叔高烯丙醇。所得的高烯丙醇还可使用叔丁基过氧化氢(TBHP)原位环氧化,以高产率(84 - 87%)得到环氧化醇。