A relay energy transfer paradigm for asymmetric photocatalyzed [4+2] cycloadditions
Summary
In asymmetric energy transfer photocatalysis, direct incorporation of conventional chiral catalysts has achieved satisfactory enantiocontrol in several transformations. However, the efficiency and even feasibility of this mode are still limited by the energy transfer barrier that arises from the inevitable catalyst-mediated spatial segregation. To overcome this underappreciated constraint, we designed a relay energy transfer catalytic mode in which the catalyst acts as a bridge for energy
Content
# A relay energy transfer paradigm for asymmetric photocatalyzed [4+2] cycloadditions
*Published: 2026 May 21*
In asymmetric energy transfer photocatalysis, direct incorporation of
conventional chiral catalysts has achieved satisfactory enantiocontrol in
several transformations. However, the efficiency and even feasibility of this
mode are still limited by the energy transfer barrier that arises from the
inevitable catalyst-mediated spatial segregation. To overcome this
underappreciated constraint, we designed a relay energy transfer catalytic mode
in which the catalyst acts as a bridge for energy transfer between the
photosensitizer and the substrate. Guided by this concept, we engineered a class
of chiral energy transfer acid catalysts capable of delivering high triplet
energy. These catalysts effectively circumvent the inherent stoichiometric
dependence on acid activators in dearomative [4+2] cyclization between
quinolines and alkenes. The tunability of side arms and the proximity of the
catalytic site to the chiral source optimize regio-, diastereo-, and
enantioselectivities.
DOI: 10.1126/science.aeb8506