Chiral functionalized bisphosphine ligands: Transition metal complexes of 1,2-bis(tert-Butylchlorophosphino)-1,2-dicarba-closo-dodecaborane(12)

When rac- or meso-1,2-bis(tert-butylchlorophosphino)-1,2-dicarba-closo-dodecaborane(12) (1a or 1b) is reacted with [M(CO)(4)(NBD)] (M = Cr, Mo, NBD = norbornadiene), [Mo(CO)(4)(EtCN)(2)] or [W(CO)(6)], rac-[Cr(CO)(4){1,2-((PBuCl)-Bu-t)(2)C2B10H10}] (2), rac- or meso-[Mo(CO)(4)(1,2-((PBuCl)-Bu-t)(2)C2B10H10}] (3a or 3b) and rac-[W(CO)(4)[1,2-((PBuCl)-Bu-t)(2)C2B10H10}] (4) could be isolated as pure diastereomers. UV irradiation of 1 with [Cr(CO)(6)] in moist THF proceeds with hydrolysis and formation of [Cr(CO)(4){1,2-(P(OH)Bu-t)(2)C2B10H10}] (5) which contains the metal complex-stabilized phosphinous acid. Compounds 2-5 were characterized spectroscopically (H-1, (31)p, B-11, C-13 NMR), by mass spectrometry and by X-ray structure determination. (c) 2009 Elsevier Ltd. All rights reserved.