Ligand maps lead to treasure! The activity of complexes of fluorophosphines (R2PF) in catalytic hydroformylation and hydrocyanation is predicted from a ligand map. However, the instability of R2PF to disproportionation is well‐documented. Examples of R2PF ligands (see scheme) are described that are stabilized to such an extent that they can be used in catalysis and are shown to be highly effective.

The homodiphosphanes CgP-PCg (1) and PhobP-PPhob (2) and the heterodiphosphanes CgP-PPhob (3), CgP-PPh(2) (4a), CgP-P(o-Tol)(2) (4b), CgP-PCy(2) (4c), CgP-P(t)Bu(2) (4d), PhobP-PPh(2) (5a), PhobP-P(o-Tol)(2) (5b), PhobP-PCy(2) (5c), PhobP-P(t)Bu(2) (5d) where CgP = 6-phospha-2,4,8-trioxa-1,3,5,7-tetramethyladamant-9-yl and PhobP = 9-phosphabicyclo[3.3.1]nonan-9-yl have been prepared from CgP(BH(3))Li or PhobP(BH(3))Li and the appropriate halophosphine. The formation of 1 is remarkably diastereoselective, with the major isomer (97% of the product) assigned to rac-1. Restricted rotation about the P-P bond of the bulky meso-1 is detected by variable temperature (31)P NMR spectroscopy. Diphosphane 3 reacts with BH(3) to give a mixture of CgP(BH(3))-PPhob and CgP-PPhob(BH(3)) which was unexpected in view of the predicted much greater electron-richness of the PhobP site. Each of the diphosphanes was treated with dimethylacetylene dicarboxylate (DMAD) in order to determine their propensity for diphosphination. The homodiphosphanes 1 and 2 did not react with DMAD. The CgP-containing heterodiphosphanes 4a-d all added to DMAD to generate the corresponding cis alkenes CgPCH(CO(2)Me)=CH(CO(2)Me)PR(2) (6a-d) which have been used in situ to form chelate complexes of the type [MCl(2)(diphos)] (7a-d) where M = Pd or Pt. The PhobP-containing heterodiphosphanes 3 and 5a-d react anomalously with DMAD and do not give the products of diphosphination. The X-ray crystal structures of the diphosphanes 2, 3, 4a, and 5a, the monoxide and dioxide of diphosphane 1, and the platinum chelate complex 7c have been determined and their structures are discussed.

Ligandenkarte führt zum Schatz! Mithilfe einer Ligandenkarte lässt sich die Aktivität von Komplexen mit Fluorphosphanen (R2PF) in der katalytischen Hydroformylierung und Hydrocyanierung vorhersagen. Beispiele von R2PF‐Liganden (siehe Schema) werden beschrieben, die gegen Disproportionierung stabilisiert sind, sodass sie in sehr effizienten Katalysen eingesetzt werden können.

The cage monophosphinites CgPOR {where CgP = 6-phospha-2,4,8-trioxa-adamantane and R = C6H5 (L a ); 2-C6H4CH3 (L b ); 2,4,6-C6H2(CH3)3 (L c ); 2,4-C6H3 tBu2 (L d ); CH3 (L e ); CH2CF3 (L f )} and diphosphinites CgPZPCg {where ZH2 = 2,2′-biphenol (L g ) or 1,2-benzenedimethanol (L h )} have been made from CgPBr and the corresponding alcohol or phenol. The cage phosphinites are remarkably stable to water. All the ligands L a−h have been tested for nickel(0)-catalyzed hydrocyanation of 3-pentenenitrile in the presence of Lewis acids (ZnCl2, Ph2BOBPh2, or iBu2AlOAliBu2), and tentative structure−activity relationships are suggested. The hydrocyanation activities obtained with catalysts derived from monophosphinite L f (with iBu2AlOAliBu2) and diphosphinite L h (with ZnCl2) are comparable with the commercial catalyst based on P(OTol)3. The complexes trans-[PtCl2(L)2] where L = L a (1a), L e (1e), and L f (1f) and the chelate cis-[PtCl2(L h )] (1h) are reported. From the νCO values for the complexes trans-[RhCl(CO)(L a−f )2] (2a−f), it is concluded that ligand L f is the most phosphite-like of the monophosphinites. Treatment of [Ni(cod)2] (cod = 1,5-cyclo-octadiene) with L h leads to a mixture of products, one of which was characterized as the binuclear [Ni2(L h )2(μ-cod)] (3h). The crystal structures of L h , 1a, 1e, 1f, 1h·2CH2Cl2, and 3h·3C6H5CH3 are reported.