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Chemistry and Biochemistry Publications

Cobalt

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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Dehydrotropylium-Co2(Co)6 Ion. Generation, Reactivity And Evaluation Of Cation Stability, Sheida Amiralaei, James Gauld, James R. Green Apr 2011

Dehydrotropylium-Co2(Co)6 Ion. Generation, Reactivity And Evaluation Of Cation Stability, Sheida Amiralaei, James Gauld, James R. Green

Chemistry and Biochemistry Publications

The dehydrotropylium–Co2(CO)6 ion was generated by the action of HBF4 or BF3OEt2 on the corresponding cycloheptadienynol complex, which in turn has been prepared in four steps from a known diacetoxycycloheptenyne complex. The reaction of the cycloheptadienynol complex via the dehydrotropylium–Co2(CO)6 ion with several nucleophiles results in substitution reactions with reactive nucleophiles (N>1) under normal conditions, and a radical dimerisation reaction in the presence of less reactive nucleophiles. Competitive reactions of the cycloheptadienynol complex with an acyclic trienynol complex show no preference for generation of the dehydrotropylium–Co2 …


Synthesis Of ‘Spacer’-Naproxen [2-(6-Methoxybiphenylen-2-Yl)Propanoic Acid] And -Isonaproxen [2-(7-Methoxybiphenylen-2-Yl)Propanoic Acid], Juan A. González Gómez, James R. Green, Peter C. Vollhardt Apr 2011

Synthesis Of ‘Spacer’-Naproxen [2-(6-Methoxybiphenylen-2-Yl)Propanoic Acid] And -Isonaproxen [2-(7-Methoxybiphenylen-2-Yl)Propanoic Acid], Juan A. González Gómez, James R. Green, Peter C. Vollhardt

Chemistry and Biochemistry Publications

The CpCo(CO)2-catalyzed cocyclization of 1,2-diethynyl- 4-methoxybenzene with alkynes can be applied to the synthesis of ‘spacer’-naproxen [2-(6-methoxybiphenylen-2-yl)propanoic acid] and its 7-methoxy isomer, ‘spacer’-isonaproxen. While unsymmetrical alkynes are incorporated without regioselectivity, the methoxy group in 6-methoxy-2,3-bis(trimethylsilyl)biphenylene directs electrophiles to C-3, thus allowing for regiochemical differentiation between the 2- and 3-positions.