Syntheses and Chemistry of Very Robust Phosphiranes

Polycyclic Phosphiranes: Synthesis of C-Substituted BABAR-Phos Compounds

“…Although the N-bonded substituent has a significant influence on the activity and selectivity of the catalyst in hydroborations [9] a chiral group as in 5c gave disappointingly no enantioselectivity. We therefore thought to introduce one substituent at the C-atom of the PC 2 heterocycle which also would lead to a break-down of the mirror symmetry of BABAR-Phos.…”

The transition metal-catalysed hydroboration reaction

“…252 Rhodium-BABAR-phos complexes were found to be remarkably stable, however regioselectivity in the catalysed hydroboration of aryl alkenes was relatively poor. 253,254 Iridium-catalysed reactions tend to produce the linear isomer. 35,116,117,156,185,[255][256][257][258] It has been suggested that this may be due to olefin insertion first into the M-B bond, as opposed to initial insertion into the M-H bond, as is the case with many rhodium catalysts.…”

“…252 Rhodium-BABAR-phos complexes were found to be remarkably stable, however regioselectivity in the catalysed hydroboration of aryl alkenes was relatively poor. 253,254…”

Reactions of Tri-tert-Butylphosphatetrahedrane as a Spring-Loaded Phosphinidene Synthon Featuring Nickel-Catalyzed Transfer to Unactivated Alkenes

“…Given the ease with which 1 reacts with silylene 2 and Ph 3 PCH 2 , we investigated phosphiranation reactions of alkenes using 1 as the phosphinidene synthon. Note that phosphiranes are interesting targets given their applications as ligands for transition-metal catalysts, − polymer precursors, , and building blocks for organophosphorus compounds . Multiply bonded late transition-metal complexes are well-known tools for forging three-membered rings, such as cyclopropanes and aziridines. − Moreover, Hillhouse and co-workers demonstrated that phosphinidene transfer to ethylene may be achieved via a nickel phosphinidene complex; therefore, we employed nickel reagents in our initial investigation.…”