Crystallization-Induced Dynamic Resolution of Stereolabile Biaryl Derivatives Involving Supramolecular Interactions

Dynamic atroposelective resolutions in mixed Cu­(II) complexes
derived
from stereolabile biphenyl-2,2′-diol and enantiopure 1,2-diamines
have been achieved by crystallization. In these cases, all 2,2′-disubstituted
biphenyl fragments in the crystal have the same configuration at the
stereogenic axis as a result of the transmission of chirality at the
molecular level from the chiral inducer (enantiopure diamine ligand)
to the dynamically racemic biaryl units by means of supramolecular
forces (metal–ligand and hydrogen bonding interactions). Stereoselective
synthetic strategies toward [Cu­(2,2′-biphenolate)­(1,2-diamine)]
complexes have been developed, and these derivatives have been characterized
and studied by X-ray diffraction. The formation of hydrogen bonds
in an intramolecular (between the biphenyl-2,2′-diol and diamine
moieties) and in an intermolecular (between the moieties of the copper
complex and cocrystallized methanol) way appears to be essential for
the induction of chirality.

通过结晶方法实现了由手性不稳定的双苯-2,2'-二醇和手性纯1,2-二胺衍生出的混合Cu(II)配合物中的动态手性选择性分辨。在这些情况下，由于分子层面上手性诱导剂（手性纯二胺配体）通过超分子力（金属-配体和氢键相互作用）将手性传递至动态外消旋的联苯单元，晶体中所有2,2'-二取代的联苯片段在立体中心轴上均具有相同的构型。针对[Cu(2,2'-联苯醇酸)(1,2-二胺)]配合物的立体选择性合成策略已得到开发，并通过X射线衍射对这些衍生物进行了表征和研究。分子内（联苯-2,2'-二醇和二胺官能团之间）以及分子间（铜配合物和共结晶甲醇的官能团之间）氢键的形成对于诱导手性似乎至关重要。