Stereoconvergent Generation of a Contrasteric syn‐Bicyclopropylidene (=syn‐Cyclopropylidenecyclopropane) by Stille‐Like Coupling |
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| Authors: | Murat Güney Selçuk Eşsiz Arif Daştan Metin Balci Ottorino De Lucchi Ertan Şahin Fabrizio Fabris |
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| Institution: | 1. A?r? ?brahim ?e?en University, Faculty of Art and Science, Department of Chemistry, TR‐04100, A?r?, Turkey;2. Atatürk University, Faculty of Science, Department of Chemistry, TR‐25240 Erzurum, Turkey (phone.: +90‐442‐2314405;3. fax: +90‐442‐2360948);4. Hakkari University, Faculty of Engineering, Department of Chemical Engineering, TR‐30000 Hakkari, Turkey;5. Middle East Technical University, Faculty of Science, Department of Chemistry, TR‐06800 Ankara, Turkey;6. Dipartimento di Chimica, Università Ca' Foscari di Venezia, Dorsoduro 2137, I‐30123 Venezia |
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| Abstract: | Stereoisomerically pure endo‐ and exo‐7‐halo‐7‐(trimethylstannyl)benzonorcar‐3‐enes (=endo‐ and exo‐(1‐halo‐1a,2,7,7a‐tetrahydro‐1H‐cyclopropab]naphthalen‐1‐yl)trimethylstannane) 4 and 6 were selectively obtained by lithium? tin or magnesium? tin transmetalation in good yields (Scheme 2 and 3). The reaction of these compounds with copper(I) thiophene‐2‐carboxylate (CuTC) produced in both cases the corresponding CS‐symmetric bicyclopropylidene (=cyclopropylidenecyclopropane) syn‐ 1 , a single diastereoisomer (Schemes 5 and 6). The structure of syn‐ 1 was undoubtedly elucidated by X‐ray single crystal diffraction. The coupling mechanism of the carbenoid cyclopropane is discussed (Scheme 7). |
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| Keywords: | Bicyclopropylidenes Cyclopropylidenecyclopropanes Carbenoids Cyclopropanes Diastereoselectivity Stille coupling X‐Ray crystallography |
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