The unexpected chemistry of a bis(phospholyl)acetylene

AbstractThe reaction of lithium 3,4‐dimethyl‐phospholide with tetrachloroethylene gives the corresponding 1,2‐bis(phospholyl)acetylene that has been characterized by X‐ray crystal structure analysis of its bis(pentacarbonylmolybdenum) complex. The reaction with sulfur leads to the corresponding disulfide that spontaneously undergoes a self‐condensation via a Diels‐‐Alder cycloaddition between the CC triple bond and the phosphole dienic system giving, after aromatization by loss of the phosphorus bridge, the corresponding 1,2‐bis(phospholyl)benzene. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:537–541, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20457