Organic Chemistry

Synthesis of Stereodefined 1,1-Diborylalkenes via Copper-Catalyzed Diboration of Terminal Alkynes



A copper-catalyzed method for the E-selective 1,1-diboration of terminal alkynes is described. The tandem process involves sequential dehydrogenative borylation of the alkyne substrate with HBdan (HBdan = 1,8-diaminonaphthalatoborane), followed by hydroboration with HBpin (HBpin = pinacolborane). This method proceeds efficiently under mild conditions, furnishing 1,1-diborylalkenes with excellent stereoselectivity and broad functional-group tolerance. Taking advantage of the different reactivities of the two boryl moieties, the products can then be employed in stepwise cross-couplings with aryl halides for the stereocontrolled construction of trisubstituted alkenes.


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Supplementary material

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Supporting Info
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