Dynamic resolution of α-halo chiral esters for the synthesis of 3-substituted piperazin-2-ones

Enantioselective Organocatalytic Synthesis of 2-Oxopiperazines from Aldehydes: Identification of the Elusive Epoxy Lactone Intermediate

“…Unfortunately, until very recently, only approaches based on chiral pool techniques were available in the arsenal of a synthetic chemist . This daunting challenge was recently addressed with complementary methods based on chiral-auxiliary-promoted dynamic resolutions and multistep metal-catalyzed processes . In 2015, Stoltz and co-workers reported an elegant palladium-catalyzed asymmetric allylic alkylation approach for the synthesis of chiral 2-oxopiperazines …”

Catalytic Dynamic Kinetic Resolutions with N‐Heterocyclic Carbenes: Asymmetric Synthesis of Highly Substituted β‐Lactones

“…[1,2] Due to the intrinsic lack of efficiency with this strategy where the theoretical yield is only 50 %, many creative dynamic kinetic resolutions (DKRs) have been developed in which > 99 % yields are possible. [3] For these processes, the rapid interconversion between each enantiomer of a starting material provides an opportunity for a selective catalyst system [4] to promote a desired reaction favoring only one enantiomer, assuming the interconversion is faster than the irreversible step. Both transition metal and enzyme-based DKR reactions have seen significant development over the past two decades.…”