Synthesis of E- and Z-trisubstituted alkenes by catalytic cross-metathesis

Article

关键词: OLEFIN-METATHESIS;    STEREOSELECTIVE-SYNTHESIS;    ALKYLIDENE COMPLEXES;    COUPLING REACTION;    ALLYLIC ALCOHOLS;    WITTIG REACTION;    MOLYBDENUM;    EFFICIENT;    ALKYNES;    CARBOMETALATION;   

DOI  :  10.1038/nature25002

来源: SCIE

【 摘 要 】

Catalytic cross-metathesis is a central transformation in chemistry, yet corresponding methods for the stereoselective generation of acyclic trisubstituted alkenes in either the E or the Z isomeric forms are not known. The key problems are a lack of chemoselectivity-namely, the preponderance of side reactions involving only the less hindered starting alkene, resulting in homo-metathesis by-products-and the formation of short-lived methylidene complexes. By contrast, in catalytic cross-coupling, substrates are more distinct and homocoupling is less of a problem. Here we show that through cross-metathesis reactions involving E-or Z-trisubstituted alkenes, which are easily prepared from commercially available starting materials by cross-coupling reactions, many desirable and otherwise difficult-to-access linear E-or Z-trisubstituted alkenes can be synthesized efficiently and in exceptional stereoisomeric purity (up to 98 per cent E or 95 per cent Z). The utility of the strategy is demonstrated by the concise stereoselective syntheses of biologically active compounds, such as the antifungal indiacen B and the anti-inflammatory coibacin D.

【 授权许可】

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