Selective preparation of 1,3-butadienyl phosphines, 1-iodo- and 1,4-diiodo-butadienyl phosphine oxides via zirconocene-mediated cross-coupling of alkynylphosphines

Stereodefined butadienyl phosphines and related derivatives were readily prepared in high yields with perfect regioselectivity via the zirconocene-mediated pair-selective coupling of alkynylphosphines with ethylene or alkynylphosphines with normal alkynes. Interesting and synthetically useful iodination reactions were found when the in situ generated α-phosphinozirconacyclopentenes or α-phosphinozirconacyclopentadienes were treated with I2.