Au-Containing All-Carbon 1,3-Dipoles: Generation and [3+2] Cycloaddition Reactions

Au-Containing All-Carbon 1,3-Dipoles: Generation and [3+2] Cycloaddition Reaction

Visible-Light-Induced Copper-Catalyzed Intermolecular Markovnikov Hydroamination of Alkenes

A visible-light-induced copper-catalyzed intermolecular hydroamination of alkenes using commercially accessible primary and secondary amines has been established. This effective method exhibits good tolerance of a broad range of functional groups and provides a facile access to an array of valuable amines with Markovnikov regioselectivity. The process can be positively expected to be used in bioactive amines, and it may provide new potential in the discovery of copper-catalyzed hydrofunctionalization reactions

Enantioselective Synthesis of Quaternary Stereocenters via Chromium Catalysis

Asymmetric allylation of aldehydes with γ-disubstituted allyl halides has been achieved in the presence of a sulfonamide/oxazoline chromium complex. A variety of synthetically useful α-homoallylic alcohols with two consecutive stereogenic centers, including one quaternary carbon, can be accessed in a highly diastereoselective and enantioselective manner

Enantioselective 1,2-Difunctionalization of 1,3-Butadiene by Sequential Alkylation and Carbonyl Allylation

A highly enantioselective three-component coupling of 1,3-butadiene with a variety of fluorinated or nonfluorinated alkyl halides and aldehydes has been achieved relying on a Cr/Co bimetallic catalysis system. The strategy established here facilitates straightforward introduction of the privileged fluoro functionalities into homoallylic alcohols from bulk feedstock materials in a highly <i>anti</i>-diastereo and enantioselective manner

Gold-Catalyzed Efficient Preparation of Linear α-Iodoenones from Propargylic Acetates

Only 2 mol % of Au(PPh3)NTf2 is needed to convert readily accessible propargylic acetates into versatile linear α-iodoenones in good to excellent yields. This reaction is easy to execute and has broad substrate scope. Good to excellent Z-selectivities are observed in the cases of aliphatic propargylic acetates derived from aldehydes

Au-Catalyzed Synthesis of (1<i>Z</i>,3<i>E</i>)-2-Pivaloxy-1,3-Dienes from Propargylic Pivalates

Propargylic pivalates with electronically unbiased internal alkynes are selectively transformed into (1Z,3E)-2-pivaloxy-1,3-dienes containing various functionalities. The unusual selectivity of 1,2-acyloxy migration over the structurally preferred 3,3-rearrangement is realized. This reaction is highly stereoselective and offers rapid access to dienes for one-pot intra-/intermolecular Diels−Alder reactions either under thermal conditions or with Lewis acid catalysis

Tetrasubstituted Carbon Stereocenters via Copper-Catalyzed Asymmetric Sonogashira Coupling Reactions with Cyclic gem-Dihaloketones and Tertiary α-Carbonyl Bromides

The construction of chiral tetrasubstituted carbon stereocenters is an ongoing challenge in synthetic organic chemistry due to its prevalence in multiple disciplines. One efficient approach is the catalytic asymmetric C–C coupling reactions of a readily available racemic tertiary alkyl electrophile by simple organic nucleophiles. While a variety of secondary alkyl halides succeeded in asymmetric Cu-catalyzed Sonogashira-type cross-coupling reactions with diverse alkynes, tertiary alkyl halides have rarely been used in this kind of coupling reaction. Herein, we demonstrate that tertiary bromides can serve as efficient coupling partners in copper/bisoxazoline phenyl amine (BOPA)-catalyzed asymmetric alkynylation, leading to synthetically and medicinally valuable tertiary C–F stereocenters and all-carbon quaternary stereocenters

PtCl₂-Catalyzed Rapid Access to Tetracyclic 2,3-Indoline-Fused Cyclopentenes: Reactivity Divergent from Cationic Au(I) Catalysis and Synthetic Potential

A PtCl2-catalyzed 3,3-rearrangement/[3+2]-cycloaddition of propargylic 3-indoleacetates is developed. Besides the efficient formation of highly functionalized tetracyclic cyclopentenes, the reaction is dramatically divergent from that catalyzed by cationic AuI. Moreover, the synthetic potential of this method is demonstrated by a succinct synthesis of the tetracyclic core of vindolinine