Chromium(II)-Catalyzed Diastereoselective Pinacol Type Cross Coupling between α,β-Unsaturated Carbonyl Compounds and Aliphatic Aldehydes
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چکیده
Synlett 2002, No. 12, Print: 02 12 2002. Art Id.1437-2096,E;2002,0,12,2015,2018,ftx,en;G26802ST.pdf. © Georg Thieme Verlag Stuttgart · New York ISSN 0936-5214 Abstract: Using only 10 mol% of CrCl2 as catalyst, acroleins and , -unsaturated ketones were coupled with aliphatic aldehydes to obtain substituted 1,2-diols using manganese powder as reducing agent and TMS-Cl as scavenger. Diastereoselectivities depend on the substituents especially on R1 of the unsaturated carbonyl compound. Formation of the syn-diols is preferred with sterically demanding R, the anti-diols are obtained with smaller substituents.
منابع مشابه
Chromium-catalyzed pinacol-type cross-coupling: studies on stereoselectivity.
A chromium-catalyzed pinacol-type cross-coupling reaction between alpha,beta-unsaturated carbonyl compounds and aldehydes is reported. Even sterically demanding substrates could be coupled to afford the corresponding pinacols in good yields. Systematic studies concerning the origin of the diastereoselectivities led to the proposal of a mechanism for this synthetically useful reaction. Acroleins...
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