Transition-metal-catalyzed dehydrocoupling of tert-butylferrocenylphosphine-borane (2) with [{Rh(mu-Cl)-(1,5-cod)}(2)] (cod = cyclooctadiene) as the catalyst gave the homocoupled product [Fc(tBu)(H)P(BH2)P(Fc)(tBu)-(BH2X)] [3; Pc = Fe(C5H5)(C5H4), X = H/Cl], while cross-dehydrocoupling with the tertiary phosphine-boranes P(tBu)(nBu)(2)(BH3) (2a) and PFh(nBu)(2)(BH3) (2b) using [RX1,5-cod)(2)]OTf (OTf = trifluoromethanesulfonate) gave the first cross-dehydrocoupled products reported to date, [Fc(tBu)(BH3)P(BH2)P(tBu)(nBu)(2)] (4) and [Fc(tBu)(BH3)P(BH2)PPh(nBu)(2)] (5), in moderate yields. Compounds 2-5 were characterized by NMR spectroscopy (H-1, C-13, P-31, and B-11), IR spectroscopy, mass spectrometry, and single-crystal X-ray structure determination.