COAP-Pd Catalyzed Asymmetric Formal [3+2] Cycloaddition for Optically Active Multistereogenic Spiro Cyclopentane-Indandiones Bearing Cyclic N-Sulfonyl Ketimine Skeletons.

We reported a chiral oxamide-phosphine ligand (COAP-Ph)-Pd-catalyzed asymmetric [3+2] cycloaddition reaction between vinyl cyclopropane compounds derived from 1,3-indanedione and 2-vinylcyclopropane-1,1-dicarboxylates with cyclic sulfonyl 1-azadienes. The corresponding reactions provided a series of enantiomerically active spiro cyclopentane-indandione and cyclopentane structures bearing three consecutive stereogenic centers in good yields with good diastereo- and enantioselectivity. The COAP-Pd complex serves not only to promote generation of chiral π-allyl-palladium intermediates and induce the asymmetry of the reaction, but also depress the background reaction.

Chiral Phosphine Ligands of COAP and SKP Switched Regiodivergent Asymmetric Allylic Alkylation of MBH Adducts.

The palladium-catalyzed highly regioselective asymmetric allylic alkylation of 3'-indolyl-3-oxindole derivatives with Morita-Baylis-Hillman (MBH) carbonates was developed to facilely construct chiral 3,3'-bisindole derivatives under mild reaction conditions. The regioselectivity (α/γ) of MBH carbonates was efficiently switched in the presence of chiral oxalamide phosphine or spiroketal-based diphosphine/Pd(0) complexes as a chiral catalyst. A series of multifunctional 3,3'-bisindole derivatives with all-carbon quaternary stereogenic centers were obtained in high yields with good to excellent enantio-, diastereo-, and regioselectivity. The present process is endowed with some salient features such as broad substrate scope, N-protecting group-free, excellent stereoselectivity, as well as adjustable regioselectivity.

COAP-Pd Catalyzed Asymmetric Allylic Alkylation of Azlactones with MBH Carbonates: Access to Unnatural α-Quaternary Stereogenic Glutamic Acid Derivatives.

A palladium-catalyzed regioselective and asymmetric allylic alkylation of azlactones with MBH carbonates has been developed with chiral oxalamide-phosphine ligands. The corresponding reaction afforded a range of optically active γ-arylidenyl glutamic acid derivatives bearing an α-chiral quaternary stereocenter in good yields with excellent linear regio- and high enantioselectivity. This protocol furnishes an alternative approach for the construction of enantio-enriched unnatural α-amino acid derivatives.

COAP/Pd-Catalyzed Linear Asymmetric Allylic Alkylation for Optically Active 3,3-Disubstituted Oxindole Derivatives with a Four-Carbon Amino Side Chain.

An asymmetric linear selective allylic alkylation of vinylaziridines with 3-aryl oxindoles has been developed by using a chiral oxamide-phosphine (COAP-Bn-OMe-p)/palladium complex in methanol, which furnished a wide variety of 3,3-disubstituted oxindole derivatives in good yields with excellent regio- and enantioselectivities.