Enantioselective Hydroaminomethylation of Olefins Enabled by Rh/Brønsted Acid Relay Catalysis

Herein, by employing a rhodium catalyst with a commercial ligand and a phosphoric acid catalyst, highly chemo-, regio-, and enantioselective hydroaminomethylation of olefins is realized through a relay catalytic hydroformylation/dynamic kinetic reductive amination process. The method features mild conditions (1 bar of syngas, room temperature in most cases), high yields (up to 99%), and high enantioselectivities (up to >99.5:0.5 er). Besides styrenes, acrylamides also provided the products with high yields and enantioselectivities. Aliphatic alkenes and vinyl esters are also applicable for the current method, albeit lower yields and enantioselectivities were obtained

Ru(II)/Organo Relay Catalytic Three-Component Reaction of 3‑Diazooxindoles, Amines, and Nitroalkene: Formal Synthesis of (−)-Psychotrimine

A highly enantioselective carbenoid-associated N–H functionalization/Michael addition cascade reaction is developed by virtue of Ru­(II)/chiral organo bifunctional catalyst relay catalysis. In this way, a variety of optically pure 3-amino-3-alkyloxindoles can be easily achieved. Moreover, on the basis of this metal/organo relay catalytic three-component protocol, a key intermediate for the formal synthesis of (−)-psychotrimine could be obtained in six steps with 25% overall yield

Pd(II)-Catalyzed Cycloisomerization/Dipolar Cycloaddition Cascade of <i>N</i>‑Arylnitrone Alkynes with Olefins

A cycloisomerization/dipolar cycloaddition tandem reaction of nitrone alkynes and electron-deficient olefins was described by employing a simple palladium catalyst. <i>N</i>-Arylnitrone alkynes, which were not well tolerated in previously reported methodologies, were successfully incorporated in the tandem reaction with generally good yields and moderate diastereoselectivities

Asymmetric Allylation of Furfural Derivatives: Synergistic Effect of Chiral Ligand and Organocatalyst on Stereochemical Control

An asymmetric allylation reaction at the benzylic position of furfurals that are easily accessed from 5-HMF, which is a biomass derivative, has been established by palladium and amine cooperative catalysis. The high levels of enantioselectivity of up to 97% enantiometric excess (ee) were enabled by the synergistic stereochemical control of a chiral TADDOL-based phosphoramidite ligand and a chiral diphenylprolinol silyl ether. The product could be feasibly transformed to chiral aryl-substituted spiroacetal via a four-step reaction sequence

Asymmetric Allylation of Furfural Derivatives: Synergistic Effect of Chiral Ligand and Organocatalyst on Stereochemical Control

An asymmetric allylation reaction at the benzylic position of furfurals that are easily accessed from 5-HMF, which is a biomass derivative, has been established by palladium and amine cooperative catalysis. The high levels of enantioselectivity of up to 97% enantiometric excess (ee) were enabled by the synergistic stereochemical control of a chiral TADDOL-based phosphoramidite ligand and a chiral diphenylprolinol silyl ether. The product could be feasibly transformed to chiral aryl-substituted spiroacetal via a four-step reaction sequence

Enantioselective Construction of Functionalized Tetrahydrocarbazoles Enabled by Asymmetric Relay Catalysis of Gold Complex and Chiral Brønsted Acid

An intramolecular hydroamination/Michael addition cascade is realized using a combination of gold­(I) complex and chiral BINOL–phosphoric acid, affording fused-tetrahydrocarbazole scaffolds in excellent yields and high enantioselectivities

Diastereoselective Carbonyl Allylation with Simple Olefins Enabled by Palladium Complex-Catalyzed C–H Oxidative Borylation

A highly diastereo­selective Pd-catalyzed carbonyl allyl­ation of aldehydes and isatins directly using simple acyclic olefins as allyl­ating reagents is described. This transformation is actually a sequential process consisting of a Pd-catalyzed oxidative allylic C–H borylation and an allyl­boration of carbonyls accelerated by phosphoric acid, wherein a wide scope of olefins could be tolerated. The oxidant is revealed to play a key role in the successful realization of the allylic C–H activation-based allylation

Diastereoselective Carbonyl Allylation with Simple Olefins Enabled by Palladium Complex-Catalyzed C–H Oxidative Borylation

A highly diastereo­selective Pd-catalyzed carbonyl allyl­ation of aldehydes and isatins directly using simple acyclic olefins as allyl­ating reagents is described. This transformation is actually a sequential process consisting of a Pd-catalyzed oxidative allylic C–H borylation and an allyl­boration of carbonyls accelerated by phosphoric acid, wherein a wide scope of olefins could be tolerated. The oxidant is revealed to play a key role in the successful realization of the allylic C–H activation-based allylation

Palladium-Catalyzed Enantioselective Heteroannulation of 1,3‑Dienes by Functionally Substituted Aryl Iodides

The first enantioselective heteroannulation of 1,3-dienes by 2-iodoanilines and 2-iodobenzylic alcohols is described. The application of a BINOL-derived phosphoramidite ligand bearing electron-withdrawing substituents is the key to obtaining high enantioselectivity. This protocol provides an efficient way to access optically active chiral indolines and isochromans from readily available starting materials

Double Chiral Induction Enables a Stereoselective Carbonyl Allylation with Simple Alkenes under the Sequential Catalysis of Palladium Complex and Chiral Phosphoric Acid

An enantioselective carbonyl allylation of aldehydes with simple alkenes has been achieved via a one-pot protocol consisting of a Pd-catalyzed allylic C–H borylation with bis­(pinane­diolato)­diboron and a chiral Brønsted acid catalyzed asymmetric allylborylation, delivering homoallylic alcohols in high yields and with excellent diastereo- and enantioselectivities. The double chiral induction of chiral allylic borate and chiral phosphoric acid allows the reaction to give excellent stereoselectivities