General Synthetic Strategies for Chiral Metallocycles

Chiral metallocycles have been constructed using three distinct strategies  

Self- and Directed-Assembly of Chiral Pt-Alkynyl Metallocycles 

FAB and MALDI-TOF MS, and IR, UV/Vis, and circular dichroism (CD) spectroscopies, and microanalysis. The limited conformational flexibility of the bridging ligand is key to the facile one-pot self-assembly of chiral molecular polygons 19-24. 

Molecular triangle lOd contains chiral dihydroxy functionalities and has been used for highly enantioselective catalytic diethylzinc additions to aromatic aldehydes, affording chiral secondary alcohols upon hydrolytic work-up, as shown in Eq. (4.2) (Table 4.2) [22]. With Ti(IV) complexes of lOd as catalyst, chiral secondary alcohols were obtained in 95% yield and 89-92% ee for a wide range of aromatic aldehydes with varying steric demands and electronic properties (Table 4.2). In comparison, when the free ligand 6,6 -dichloro-4,4 -diethynyl-2,2 -binaphthol was used instead of 

Interestingly, the steric congestion around the chiral dihydroxy groups in isomeric metallacydophane 18c prevented its reaction with TifO Pr) to form active catalysts 

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