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A copper‐catalyzed dearomative alkynylation of pyridines is reported with excellent regio‐ and enantioselectivities. The synthetically valuable enantioenriched 2‐alkynyl‐1,2‐dihydropyridine products afforded are generated from the readily available feedstock, pyridine, and commercially available terminal alkynes. The three‐component reaction between a pyridine, a terminal alkyne, and methyl chloroformate employs copper chloride and StackPhos, a chiral biarylP,N‐ligand, as the catalytic system. Under mild reaction conditions, the desired 1,2‐addition products are delivered in up to 99 % yield with regioselectivity ratios up to 25 : 1 and enantioselectivities values of up to 99 % ee. Activated and non‐activated terminal alkynes containing a wide range of functional groups are well tolerated. Even acetylene gas delivered mono‐alkynylated products in high yield and ee. Application of the methodology in an efficient enantioselective synthesis of the chiral piperidine indolizidine, coniceine, is reported.

A copper‐catalyzed dearomative alkynylation of pyridines is reported with excellent regio‐ and enantioselectivities. The synthetically valuable enantioenriched 2‐alkynyl‐1,2‐dihydropyridine products afforded are generated from the readily available feedstock, pyridine, and commercially available terminal alkynes. The three‐component reaction between a pyridine, a terminal alkyne, and methyl chloroformate employs copper chloride and StackPhos, a chiral biarylP,N‐ligand, as the catalytic system. Under mild reaction conditions, the desired 1,2‐addition products are delivered in up to 99 % yield with regioselectivity ratios up to 25 : 1 and enantioselectivities values of up to 99 % ee. Activated and non‐activated terminal alkynes containing a wide range of functional groups are well tolerated. Even acetylene gas delivered mono‐alkynylated products in high yield and ee. Application of the methodology in an efficient enantioselective synthesis of the chiral piperidine indolizidine, coniceine, is reported.

Here we report a strategy for the systematic variation of atropisomeric C₁‐symmetric P,N ligands to incrementally change the position of the groups within the chiral pocket without modifying their steric parameters. More specifically, the effects of systematic modification of the nitrogen heterocycle in atropisomeric C₁‐symmetric stack ligands have been investigated in this study. The versatility and applicability of this approach has been demonstrated in mechanistically distinct catalytic enantioselective transformations, resulting in the identification of a P,N‐ligand for a highly enantioselective synthesis of organoboranes.

Here we report a strategy for the systematic variation of atropisomeric C₁‐symmetric P,N ligands to incrementally change the position of the groups within the chiral pocket without modifying their steric parameters. More specifically, the effects of systematic modification of the nitrogen heterocycle in atropisomeric C₁‐symmetric stack ligands have been investigated in this study. The versatility and applicability of this approach has been demonstrated in mechanistically distinct catalytic enantioselective transformations, resulting in the identification of a P,N‐ligand for a highly enantioselective synthesis of organoboranes.

Asymmetric allylic alkylation (AAA) is a powerful method for the formation of highly useful, non‐racemic allylic compounds. Here we present a complementary enantioselective process that generates allylic lactones via π‐acid catalysis. More specifically, a catalytic enantioselective dehydrative lactonization of allylic alcohols using a novel Pd^II‐catalyst containing the imidazole‐basedP,N‐ligand (S)‐StackPhos is reported. The high‐yielding reactions are operationally simple to perform with enantioselectivities up to 99 %ee. This strategy facilitates the replacement of a poor leaving group with what would ostensibly be a better leaving group in the product avoiding complications arising from racemization by equilibration.

Asymmetric allylic alkylation (AAA) is a powerful method for the formation of highly useful, non‐racemic allylic compounds. Here we present a complementary enantioselective process that generates allylic lactones via π‐acid catalysis. More specifically, a catalytic enantioselective dehydrative lactonization of allylic alcohols using a novel Pd^II‐catalyst containing the imidazole‐basedP,N‐ligand (S)‐StackPhos is reported. The high‐yielding reactions are operationally simple to perform with enantioselectivities up to 99 %ee. This strategy facilitates the replacement of a poor leaving group with what would ostensibly be a better leaving group in the product avoiding complications arising from racemization by equilibration.

In this work, we report enantioselective orthogonal tandem catalysis for the one pot conversion of Meldrum's acid derivatives and alkynes into δ‐lactones. This new transformation, which resembles a formal [4+2] cycloaddition with concomitant decarboxylation and loss of acetone, proceeds in high yields and excellent enantioselectivity (up to 99 %ee) over a broad substrate scope. The products are densely functionalized and ripe for further transformations, as demonstrated here by both ring‐opening reactions and reduction to saturated lactones. It was discovered that a new and serendipitously formed Ag^I‐Me‐StackPhos complex efficiently catalyzes the highly selective 6‐endo‐dig cyclization, completely reversing the regiochemistry that has been previously reported in related systems. More generally, in this study we identify a pair of compatible catalysts for alkyne difunctionalization that operate concurrently, which enable the alkyne to act as both a nucleophile and an electrophile in sequential one‐pot transformations.

In this work, we report enantioselective orthogonal tandem catalysis for the one pot conversion of Meldrum's acid derivatives and alkynes into δ‐lactones. This new transformation, which resembles a formal [4+2] cycloaddition with concomitant decarboxylation and loss of acetone, proceeds in high yields and excellent enantioselectivity (up to 99 %ee) over a broad substrate scope. The products are densely functionalized and ripe for further transformations, as demonstrated here by both ring‐opening reactions and reduction to saturated lactones. It was discovered that a new and serendipitously formed Ag^I‐Me‐StackPhos complex efficiently catalyzes the highly selective 6‐endo‐dig cyclization, completely reversing the regiochemistry that has been previously reported in related systems. More generally, in this study we identify a pair of compatible catalysts for alkyne difunctionalization that operate concurrently, which enable the alkyne to act as both a nucleophile and an electrophile in sequential one‐pot transformations.