Chiral Selection in the Formation of Borates from Racemic Binaphthols and Related Diols

Feb 152011
 

CrystEngComm (2011), 13(8) 2923-2929.    [ doi:10.1039/c0ce00709a ]

A series of racemic or stereochemically labile chiral borate anions based on the 2,20-biphenol motif was
investigated. All borates were homochiral in the solid state, although in some cases the heterochiral
diastereomers were computed to be thermodynamically preferred (DFT). The crystallographic
preference for the homochiral diastereomer was attributed to its lower bulk, higher molecular
symmetry, and the therewith associated better packing ability.

Structure of the Month – February 2011

Feb 012011
 

Presented by:  Dr. Andrew D. Schwarz & Liban M. A. Saleh
Research Leader:  Prof. Philip Mountford & Prof. Simon Aldridge
Published:  Journal of the American Chemical Society

Transition-metal boryl compounds (L)M(BX2)x, containing 2‑center, 2‑electron σ‑bonds have been a topic of outstanding interest due to pivotal roles in a variety of catalytic and stoichiometric transformations, e.g. hydroboration and diboration of C–C π-bonds, and functionalization of alkane and arene C‑H bonds. To date, virtually all boryl complexes have been prepared either by B‑X (X = H or halogen) or B‑B oxidative addition to a low oxidation state (L)M species, or by nucleophilic attack of a [(L)M]‑ anion on a XBR2 or related source of the boryl moiety. However, utilisation of the nucleophilic Li{B(NArCH)2}(THF)2 (Ar = 2,6‑C6H3iPr2), allows access to rare earth metal boryl compounds.  Data were collected on a small colourless crystal (0.05 × 0.05 × 0.05 mm) using the new Oxford Diffraction (Agilent) SuperNova diffractometers and copper radiation.

Structure of the Month - February 2011

Structure of the Month – February 2011