Some Reactions of gem‐Dibromocyclopropanes and Metal Carbonyls |
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| Authors: | Shaw‐Tao Lin Chuan‐Chen Lee Mei‐Fang Ding David W. Liang An‐Ting Jeng |
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| Affiliation: | 1. Department of Applied Chemistry, Providence University, Sha‐Lu, Taichung 43301, Taiwan, R.O.C.;2. Department of Health and Nutrition Biotechnology, Asia University, Wufong, Taichung 41354, Taiwan, R.O.C. |
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| Abstract: | A series of gem‐dibromocyclopropanes were treated with various metal complexes. Among the metal complexes, Ru(CO)2(PPh3)3, Ru(CO)3(PPh3)2, and Mo(CO)6 were able to remove a bromine atom from 1,1‐dibromo‐2‐phenylcyclopropanes ( 1 ) to yield a series of corresponding of 1‐bromo‐2‐phenylcyclopropanes ( 2 ). Upon the treatment of 1 with Cr(CO)6 in DMSO, a series of allenes were obtained in good yields. The correlation between the rate of formation of allenes and the substituents on the benzene gives a negative coefficient which suggests the dibromocyclopropanes possesses as an electrophile toward to Cr(CO)6. In the presence of Cr(CO)6, gem‐dibromobicyclo[n,1,0]alkanes ( 4 ) in DMF or DMSO solution underwent the cleavage of carbon‐bromine bond followed by ring‐expansion and coupling reaction to form bicycloalkenes 7 . |
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| Keywords: | gem‐Dibromocyclopropane Chromium carbonyl Debromination Ring‐opening Coupling |
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