2‐Aryl‐dibenzo‐1,2‐oxaphosphorine as a ligand in borane and in Pt(II) complexes

A Highly Diastereoselective Route to Dinaphtho[c,e][1,2]oxaphosphinines and Their Application as Ligands in Homogeneous Catalysis

“…[5] Of considerable interest are 1,2-oxaphosphinines. Dibenzo[c,e] [1,2]oxaphosphinines, investigated by the Keglevich group, [6] for example, are useful substrates for Pd-and Ni-catalysed arylations. [7] These heterocycles have also been used as ligands in the Ni-catalysed hydrocyanation of butadienes [8] and in the regioselective Rh-catalysed hydroformylation of olefins.…”

“…[11] Later on, Pastor et al suggested a one-pot synthesis involving cyclization of 1 in PCl 3 with ZnCl 2 as catalyst at high temperature. [12,13] The chloro compound 3 [6][7][8][9][10][11][12] represents an interesting starting material for subsequent substitution reactions on the trivalent phosphorus. Inspired by these results and as part of our ongoing studies concerned with the synthesis of chiral P-ligands, [14] we became interested in the synthesis of sterically more hindered compounds such as the binaphthyl [1,2]oxaphosphinines 7 (Scheme 2).…”

Conversion of Dibenzoxaphosphinines into 2‐Hydroxybiphenyl‐2′‐ylphosphane Ligands and Their BH3 Adducts: The O–Hδ+···Hδ––B Hydrogen–Hydrogen Bond

“…deviation of a least-squares fit of 0.02 Å; the biphenyl interplanar angles are both 76°. The P-C bond lengths are similar to those of the related borane-free tert-butyl(2-hydroxybiphenylyl)phenylphosphane [5] but the angles C12-P1-C31 and C12-P1-C38 are somewhat larger [105.82(8) and 111.12(10) vs. 101.89 (9) and 103.18(10)°], because the BH 3 substituents have replaced the lone-electron pairs. The P-B bonds of 6b are slightly longer than in Ph 3 P-BH 3 (1.917 Å) [21] and Me 3 P-BH 3 (1.901 Å [22] ), which may be associated with an O-H···H-B hydrogen-hydrogen bond to the neighbouring molecule leading to the formation of chains of molecules.…”

“…of methyllithium, 2-methoxy-or 2,4-dimethoxyphenyllithium led to substitution of the chloride and ring-opening metathesis to give, after treating the lithium salts with excess ClSiMe 3 , the 2-(trimethylsilyloxy)biphenylylphosphanes 2e-g. NMR analyses showed analogous behaviour for phenyllithium. After hydrolysis, the phosphorus resonance (δ 31 P = -12.1 ppm) of the known 2-hydroxybiphenyl-2Ј-yldiphenylphosphane [9] was observed.…”

“…[9,10] In a patent, coupling of 1 Cl with organolithium compounds has been claimed. [12] Although phenols, alcohols and amines allow selective monosubstitution of benzo-or naphtho-annulated chloro-1,2-oxaphosphinines to yield catalytically valuable heterocyclic annulated oxaphosphinine ligands, [13][14][15] reactions with organometallic reagents seem to be less selective.…”