Rhodium-catalyzed cross-aldol reaction: in situ aldehyde-enolate formation from allyloxyboranes and primary allylic alcohols.
نویسندگان
چکیده
Significance: Aldol reactions in which the aldol donor is derived from an aldehyde, are particularly challenging. This report describes a strategy in which aldehyde enolates are generated in situ by rhodium-catalyzed isomerization of triallylboroxanes. High syn-selectivity is obtained for a variety of aldehyde-donor and -acceptor partners. Comment: Remarkably, the use of triallyloxyboranes is not required; simple primary and secondary allylic alcohols also undergo the isomerization– cross-aldol sequence with similar levels of reactivity and selectivity, presumably through a rhodiumenolate or -enol mechanism. R1 H O O 3B R2 [{Rh(cod)Cl}2] (1.25 mol%) dippf (2.5 mol%) 1,4-dioxane, r.t. OH
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ورودعنوان ژورنال:
- Angewandte Chemie
دوره 51 41 شماره
صفحات -
تاریخ انتشار 2012