Chiral relay approach

Davies, Renaud, and Sibi independently reported the chiral relay approach to control the enhanced steric extension inside a substrate to achieve increased asymmetric induction. However, as our study proves, the asymmetric activation of a tropos catalyst clearly differs from the chiral relay approach, in which substrate conformational control is utilized, since asymmetric activation controls the chiral environment of a tropos catalyst by the addition of a chiral external source (a chiral activator). 

The relay catalysis combining a mechanistically distinct transition metal catalyst and an organocatalyst for one cascade has stimulated intensive interest in recent years, as it could potentially enable highly efficient and/or unprecedented transformations in a one-pot operation. Indeed, excellent transformations have been established by this approach. One elegant example is relay catalysis using a rhodium complex/chiral Brpnsted acid binary system (Scheme 5.87) [88]. It is believed that the first catalytic... 

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