Cationic iridium complexes of the Xantphos ligand. Flexible coordination modes and the isolation of the hydride insertion product with an alkene

Dehydrogenative Boron Homocoupling of an Amine‐Borane

“…Instead a simple inversion of the Xantphos ligand would account for the observed C 2 symmetry. Such behavior has been noted previously 30. Cooling a solution (CD 2 Cl 2 ) of 4 to 218 K arrests this process so that, for example, two different Rh‐ H ‐B ( δ =−8.02, −8.55 ppm) and 31 P ( δ =29.0 ppm, J (RhP) 164 Hz; δ =28.2 ppm, J (RhP) 168 Hz) environments are observed, the latter in an ABX pattern.…”

Dehydrogenative Boron Homocoupling of an Amine‐Borane

“…Such behavior has been noted previously. [30] Cooling a solution (CD 2 Cl 2 ) of 4 to 218 K arrests this process so that, for example, two different Rh-H-B (d = À8.02, À8.55 ppm) and 31 P (d = 29.0 ppm, J(RhP) 164 Hz; d = 28.2 ppm, J(RhP) 168 Hz) environments are observed, the latter in an ABX pattern. These upfield chemical shifts are also consistent with significant B-H-Rh interactions.…”

Mechanism and Stereoselectivity of the Elementometalation Process of Activated Alkyne RCCR(RCO2Me) by Cp2TaH3

“…It is considered as the fundamental chemical step in several catalytic cycles and frequently leads to reactive intermediates. The olefin insertion into a MH bond is a key step in the catalytic cycles proposed for olefin functionalization reactions and leads to the formation of alkyl metal intermediates . The acetylene insertion into the MH bond also plays an important role in a number of catalytic processes, such as hydrogenation or polymerization reaction, which receives considerable attention due to its utility in organic syntheses .…”