Phosphophosphidites Derived from BINOL

Phosphophosphidites of the type R 2 P–P(binol) [where binol = the dianion of (S)‐1,1′‐bi‐2‐naphthol] are the phosphorus analogues of the ubiquitous phosphoramidites, R 2 N–P(binol) and are readily accessed by the chlorosilane elimination reaction between R 2 P–SiMe 3 and Cl–P(binol). The crystal structure of i Pr 2 P–P(binol) ( 1 ) has been determined and shows a P–P bond length in the normal range. The solution reactions of 1 have been investigated, principally by 31 P NMR spectroscopy which has revealed that: (a) in contrast to the phosphoramidites, 1 is extremely moisture sensitive; (b) the P–P bond in 1 is cleaved upon reaction with H 2 O, MeOH or mesitol; (c) the P–O bonds in 1 are cleaved upon reaction with pyrrolidine; (d) the integrity of 1 is retained upon coordination to BH 3 or Mo 0 . The crystal structure of cis ‐[Mo(CO) 4 ( 1 ) 2 ] shows that 1 is bound to the Mo at the P(binol) site and the ν CO of 2032 cm ‐1 indicates that 1 has similar ligand properties to a phosphonite.