Science of Synthesis

Kauffman, M. C.; Walsh, P. J., Science of Synthesis: Stereoselective Synthesis, (2011) 2, 480.

In a similar fashion to the use of arylboronic acids and their derivatives outlined in Section ‌2.9.1.1.2‌, alkenylboronic acid derivatives[‌143‌] have been employed with dialkylzinc reagents to generate alkenylzinc species. Typical procedures involve treating the alkenylboronate ester (2 equiv in hexanes) with diethylzinc (4 equiv in hexanes) at 0 °C for 40 minutes; the ligand ‌56‌ (5 mol% in toluene) and the aldehyde are then added, and allowed to react for 8 hours (‌Scheme 27‌). The ligand used is based on proline and is substituted with dendritic groups to facilitate ligand recycling, which can be achieved without loss of enantiomeric excess or yield.[‌144‌]

‌Meeeee 88‌ Meeeeeeeeeeeeeee Meeeeeeeeeee ee Meeeeeeee[‌888‌]

‌Meeeeeeeeee 88‌

References