Construction of planar chiral [2,2]paracyclophanes via photoinduced cobalt-catalyzed desymmetric addition

Planar chiral [2,2]paracyclophanes (PCPs) are widely used in materials science and asymmetric syntheses. Therefore, synthetic and material chemists have focused on the efficient and selective construction of planar chiral PCPs for decades. Herein, we present a photoinduced cobalt-catalyzed desymmetric addition of pseudo-para-diformyl and pseudo-gem-diformyl PCP, enabling the synthesis of planar chiral PCP alcohols with both planar and central chiralities. This method delivers 48 examples with yields up to 87%, diastereomeric ratios greater than 19:1, and an enantiomeric excess exceeding 99%. This protocol provides a original and efficient approach for the synthesis of planar chiral PCPs.