Intermolecular Enantioselective Dearomatization Reaction of β-Naphthol Usingmeso-Aziridine: A Bifunctional In Situ Generated Magnesium Catalyst

Palladium(0)-Catalyzed Intermolecular Carbocyclization of (1,n)-Diynes and Bromophenols: An Efficient Route to Tricyclic Scaffolds

A novel palladium(0)-catalyzed dearomative cyclization reaction of bromophenols with (1,n)-diynes has been developed for building two new types of tricyclic architectures containing a quaternary carbon center. This method employs inexpensive bromophenols, and easily accessible tethered diynes. It exhibits a broad substrate scope and tolerates various functional groups. Preliminary results with commercially available chiral ligands indicate that enantioselective variants are feasible for both cyclization processes.

Construction of spirocarbocycles via gold-catalyzed intramolecular dearomatization of naphthols

A highly efficient, gold-catalyzed intramolecular dearomatization reaction of naphthols via 5-endo-dig cyclization is described. This facile and direct approach furnishes spirocarbocycles in excellent yields under mild conditions.

Chemo-, Diastereo-, and Enantioselective Iridium-Catalyzed Allylic Intramolecular Dearomatization Reaction of Naphthol Derivatives

An iridium-catalyzed intramolecular asymmetric allylic dearomatization reaction of naphthol derivatives is described. Challenges confronted in this reaction include chemoselectivity between carbon and oxygen atoms as nucleophilic centers, diastereoselectivity when contiguous chiral centers are generated, and enantioselective control for constructing an all-carbon quaternary stereocenter. In the presence of an iridium catalyst generated from [{Ir(dbcot)Cl}2] (dbcot=dibenzocyclooctatetraene) and a new THQphos (tetrahydroquinolinedinaphthophosphoramidite) ligand, various spironaphthalenones were obtained with up to greater than 95:5 C/O selectivity, greater than 95:5 d.r., and 99 % ee, thus providing a general method for the dearomatization of naphthols.

Catalytic asymmetric dearomatization (CADA) reactions of phenol and aniline derivatives

In this tutorial review, an up to date summary of recent progress in catalytic asymmetric dearomatization (CADA) reactions of phenol and aniline derivatives is presented.

Asymmetric dearomatization of phenols

This review summarizes the recent advances in the field of asymmetric dearomatization of phenols and their applications in the total synthesis of some complex natural products.

A copper catalyzed azidation and peroxidation of β-naphthols via an oxidative dearomatization strategy

Synthesis of quaternary azides and peroxides from 2-naphthol derivatives using a Cu-catalyst by varying reaction conditions.

Simple magnesium catalyst mediated γ-butyrolactams in desymmetrization of meso-aziridines

The first α-sp²-carbon of carbonyl compounds attacked catalytic desymmetrization reaction of aziridines is disclosed by employing a simple in situ generated magnesium catalyst.

Rapid assembly of spirocycles with phenol-derived biaryls with alkynes using an oxidative C–H activation/dearomatization strategy

The synthesis of spirocyclohexadienones from phenol-derived biaryls was accomplished by using a transition-metal-catalyzed C–H activation/dearomatization strategy.

Dearomatization of Indoles via Palladium-Catalyzed Allylic C-H Activation

The first Pd-catalyzed allylic dearomatization of substituted indoles triggered by C-H bond activation is reported. The presence of a catalytic amount of 2,5-DMBQ is proven to be a key factor for the high yield. This one-pot tandem allylic C-H activation/dearomatization sequence provides a straightforward access to 3,3-disubstituted indolines.

Construction of Vicinal Tetrasubstituted Stereocenters with a C-F Bond through a Catalytic Enantioselective Detrifluoroacetylative Mannich Reaction

An efficient asymmetric detrifluoroacetylative Mannich reaction of 2-fluoro-1,3-diketones/hydrates with isatin-derived ketimines catalyzed by a chiral copper(II)-diamine complex has been realized. The reaction afforded a series of 3-substituted 3-amino-2-oxindoles bearing fluorine-containing vicinal tetrasubstituted stereocenters in high yields (up to 99%) with excellent diastereoselectivities (up to >20:1 dr) and enantioselectivities (up to 94% ee).

Organocatalytic asymmetric chlorinative dearomatization of naphthols

An organocatalytic asymmetric chlorinative dearomatization of naphthols was realized for the first time, providing chiral naphthalenones with a Cl-containing all-substituted stereocenter in excellent yields and enantioselectivity (up to 97% yield and 96% ee). The reaction features mild reaction conditions, good tolerance of diverse functional groups and simple reaction operation.

Asymmetric Dearomatization of Naphthols via a Rh-Catalyzed C(sp²)-H Functionalization/Annulation Reaction

A Rh-catalyzed enantioselective dearomatization of 1-aryl-2-naphthols with internal alkynes via C-H functionalization reaction was achieved. In the presence of a chiral Cp/Rh catalyst and combined oxidants of Cu(OAc)2 and air (oxygen), various highly enantioenriched spirocyclic enones bearing an all-carbon quaternary stereogenic center could be synthesized in 33-98% yields with up to 97:3 er.

Palladium-Catalyzed Dynamic Kinetic Asymmetric Transformation of Racemic Biaryls: Axial-to-Central Chirality Transfer

The first dynamic kinetic asymmetric transformation of racemic biaryl substrates on the basis of axial-to-central chirality transfer has been realized. Chiral Pd-NHC complexes were found to catalyze the dynamic kinetic asymmetric spiroannulation of 4-(2-bromoaryl)-naphthalen-1-ols (or 2'-bromo-[1,1'-biphenyl]-4-ols) with internal alkynes, affording a series of enantioenriched spirocyclic products bearing an all-carbon quaternary stereocenter in good yields (up to 95%) with excellent enantioselectivities (up to 97% ee).

C–F bond substitution via aziridinium ion intermediates

A mild and distinct methodology for instantaneous β-amino fluoride substitution mediated by La[N(SiMe₃)₂]₃ has been developed. The reaction proceeds via a reactive aziridinium ion intermediate, which readily reacts with various nucleophiles. This allows the use of fluorine as a modular functionality and further expands the role of aziridinium ions in organic synthesis.