Ag(I)-Catalyzed Aminofluorination of Alkynes: Efficient Synthesis of 4‑Fluoroisoquinolines and 4‑Fluoropyrrolo[α]isoquinolines

A silver-catalyzed intramolecular oxidative aminofluorination of alkynes has been developed by using NFSI as a fluorinating reagent. This reaction represents an efficient method for the synthesis of various 4-fluoroisoquinolines and 4-fluoropyrrolo[α]isoquinolines

Ag(I)-Catalyzed Aminofluorination of Alkynes: Efficient Synthesis of 4‑Fluoroisoquinolines and 4‑Fluoropyrrolo[α]isoquinolines

A silver-catalyzed intramolecular oxidative aminofluorination of alkynes has been developed by using NFSI as a fluorinating reagent. This reaction represents an efficient method for the synthesis of various 4-fluoroisoquinolines and 4-fluoropyrrolo[α]isoquinolines

Palladium-Catalyzed C–C Triple Bond Cleavage: Efficient Synthesis of 4<i>H</i>‑Benzo[<i>d</i>][1,3]oxazin-4-ones

Described herein is a new transformation of azidoalkynes by using a palladium catalyst, which involves a tandem process of aminopalladation of the alkyne and oxidative rearrangement. The reaction affords a variety of 4<i>H</i>-benzo­[<i>d</i>]­[1,3]­oxazin-4-ones. Mechanism studies support a Pd-catalyzed aminopalladation/oxidation/Baeyer–Villiger fragmentary sequence

Pd-Catalyzed Intramolecular Aminohydroxylation of Alkenes with Hydrogen Peroxide as Oxidant and Water as Nucleophile

A palladium-catalyzed intramolecular aminohydroxylation of alkenes was developed, in which H₂O₂ was applied as the sole oxidant. A variety of related alkyl alcohols could be successfully obtained with good yields and excellent diastereoselectivities, which directly derived from oxidation cleavage of alkyl C-Pd bond by H₂O₂. Facile transformation of these products provided a powerful tool toward the synthesis of 2-amino-1,3-diols and 3-ol amino acids. Preliminary mechanistic studies revealed that major nucleophilic attack of water (S_N2 type) at high-valent Pd center contributes to the final C-O­(H) bond formation

Pd(II)-Catalyzed Aminofluorination of Alkenes in Total Synthesis 6‑(<i>R</i>)‑Fluoro­swainsonine and 5‑(<i>R</i>)‑Fluoro­febrifugine

The total syntheses of two fluorinated alkaloids, 6-(<i>R</i>)-fluoro­swainsonine and 5-(<i>R</i>)-fluoro­febrifugine, are described. Both encompass (4a<i>S</i>,7<i>R</i>,8a<i>R</i>)-7-fluoro-5-tosylhexa­hydro-4<i>H</i>-[1,3]­dioxino­[5,4-<i>b</i>]­pyridine as a key synthon which is obtained through a further optimized palladium-catalyzed aminofluorination of alkenes with high diastereoselectivity. 6-(<i>R</i>)-Fluoroswainsonine is synthesized from the key synthon in 14 steps, and 5-(<i>R</i>)-fluorofebrifugine requires a sequential 15-step transformation

One-Pot Synthesis of 1‑(Trifluoromethyl)-4-fluoro-1,2-dihydroisoquinolines and 4,4-Difluoro-1,2,3,4-tetrahydroisoquinolines

A cascade approach to 1-(trifluoromethyl)-4-fluoro-1,2-dihydroisoquinolines and 4,4-difluorotetrahydroisoquinolines has been developed. The procedure involves a silver-catalyzed intramolecular aminofluorination of alkyne. This one-pot reaction provides an efficient way to synthesize various fluorinated isoquinolines

Palladium-Catalyzed Intramolecular Aminotrifluoromethoxylation of Alkenes

The first catalytic trifluoromethoxylation of unactivated alkenes has been developed, in which Pd­(CH₃CN)₂Cl₂ was used as catalyst, AgOCF₃ as trifluoromethoxide source, and Selectfluor-BF₄ as oxidant. A variety of 3-OCF₃ substituted piperidines were selectively obtained in good yields. Direct evidence was provided to address the facile reductive elimination of Pd^IV–OCF₃ complex to form sp³ C–OCF₃ bond

Palladium-Catalyzed Intramolecular Aminotrifluoromethoxylation of Alkenes

The first catalytic trifluoromethoxylation of unactivated alkenes has been developed, in which Pd­(CH₃CN)₂Cl₂ was used as catalyst, AgOCF₃ as trifluoromethoxide source, and Selectfluor-BF₄ as oxidant. A variety of 3-OCF₃ substituted piperidines were selectively obtained in good yields. Direct evidence was provided to address the facile reductive elimination of Pd^IV–OCF₃ complex to form sp³ C–OCF₃ bond

Palladium-Catalyzed Intramolecular Aminoacetoxylation of Unactivated Alkenes with Hydrogen Peroxide as Oxidant

A palladium-catalyzed intramolecular aminoacetoxylation of unactivated alkenes was developed in which H₂O₂ was used as the sole oxidant. A variety of 3-acetoxylated piperidines were obtained in good yields with good to excellent regio- and diastereoselectivities. Mechanistic study revealed that the addition of di­(2-pyridyl) ketone (dpk) ligand was crucial to promote the oxidative cleavage of the C–Pd­(II) bond by H₂O₂ to give the C–OAc bond

Palladium-Catalyzed Intermolecular Azidocarbonylation of Alkenes via a Cooperative Strategy

A novel intermolecular β-azidocarbonylation reaction of alkenes has been developed in which a combination of iodine­(III)-mediated alkene activation and palladium-catalyzed carbonylation was demonstrated as an efficient strategy for the difunctionalization of alkenes. A variety of β-azido carboxylic esters were obtained from mono- and 1,1-disubstituted terminal alkenes with excellent regioselectivities. In addition, the introduced azido group can be reduced to an amine group, providing a facile access to β-amino acid derivatives from simple olefins