Dihalogenocarbene precursor

The work of Seyferth s group on phenyl(trihalogenomethyl)mercury compounds as dihalogenocarbene precursors has been reviewed. "... 

Following the pathway to diphosphiranes via the [2+1] cycloaddition between diphosphenes and dihalogenocarbenes Yoshifuji reacted diphosphene ( )-l with a mixture of carbon tetrachloride and -butyllithium. ( )-Diphosphirane 2 was obtained in 20% yield, while 64% of precursor ( )-l were recovered <2002CC3012> (Equation 1). 

Thermal decomposition to a dihalogenocarbene from an organomercury precursor in the presence of substituted benzaldehydes and dimethyl acetylene dicarboxylate produces 2-halogeno-5-arylfuran-3,4-dicarboxylates 292 in isolated yields that range from 13 to 64%. These products appear to be the... 

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