Rhodium(II)-Catalyzed Asymmetric Sulfur(VI) Reduction of Diazo Sulfonylamidines

Diazo sulfonylamidines readily undergo enantioselective oxygen transfer from sulfur to carbon atom in the presence of chiral rhodium­(II) carboxylates resulting in chiral sulfinylamidines. This unusual asymmetric atom transfer “reduction” occurs rapidly under mild conditions, and sulfinylamidines are obtained in excellent yield

<i>Para</i>-Selective Halogenation of Nitrosoarenes with Copper(II) Halides

The <i>para</i>-selective direct bromination and chlorination of nitrosoarenes with copper­(II) bromide and chloride is reported. Under mild reaction conditions, a range of halogenated arylnitroso compounds are obtained in moderate to good yields with high regioselectivity. Additionally, the versatility of the method is demonstrated by the development of a one-pot procedure to obtain the corresponding <i>para</i>-halogenated aniline- and nitrobenzene derivatives

Palladium-Catalyzed Allylic C−OH Functionalization for Efficient Synthesis of Functionalized Allylsilanes

A new method is described for palladium-catalyzed allylic silylation using allylic alcohols and disilanes as precursors. The reactions proceed smoothly under mild and neutral conditions, and this method is suitable for synthesis of regio- and stereodefined allylsilanes. The presented silylation reaction can be easily extended to include synthesis of allylboronates by change of the dimetallic reagent. The presented synthetic procedure offers a broad platform for the selective synthesis of functionalized allyl metal reagents, which are useful precursors in advanced organic chemistry and natural product synthesis

Nickel-Catalyzed 1,2-Aminoarylation of Oxime Ester-Tethered Alkenes with Boronic Acids

A nickel-catalyzed 1,2-aminoarylation of oxime-ester-tethered alkenes with boronic acids was developed. A variety of pyrroline derivatives were synthesized in good yields via the successive formation of C­(sp³)–N and C­(sp³)–C­(sp²) bonds. For cyclobutanone-derived oxime esters, the reaction provided aliphatic nitriles incorporating an aromatic group in the γ-position. A mechanism involving iminyl radical and carbon-centered radical intermediates was proposed

Diastereoselective Synthesis of Polycyclic Indolizines with 2‑(2-Enynyl)pyridines and Enamines

A diastereoselective metal-catalyzed reaction of 2-(2-enynyl)­pyridines and cyclic enamines is reported. The method provides access to a variety of substituted indolizine derivatives by variation of the enyne component and the reaction conditions. Performing the reaction using a preformed enamine led to the formation of polycyclic indolizines. With <i>in situ</i> generated enamines, ketone-containing indolizine derivatives were obtained. An asymmetric reaction of 2-(2-enynyl)­pyridines and enamines generated from an aldehyde and a catalytic amount of amine is presented

Arylation of Rhodium(II) Azavinyl Carbenes with Boronic Acids

A highly efficient and stereoselective arylation of in situ-generated azavinyl carbenes affording 2,2-diaryl enamines at ambient temperatures has been developed. These transition-metal carbenes are directly produced from readily available and stable 1-sulfonyl-1,2,3-triazoles in the presence of a rhodium carboxylate catalyst. In several cases, the enamines generated in this reaction can be cyclized into substituted indoles employing copper catalysis

Arylation of Rhodium(II) Azavinyl Carbenes with Boronic Acids

A highly efficient and stereoselective arylation of in situ-generated azavinyl carbenes affording 2,2-diaryl enamines at ambient temperatures has been developed. These transition-metal carbenes are directly produced from readily available and stable 1-sulfonyl-1,2,3-triazoles in the presence of a rhodium carboxylate catalyst. In several cases, the enamines generated in this reaction can be cyclized into substituted indoles employing copper catalysis

Stereoselective 1,3-Insertions of Rhodium(II) Azavinyl Carbenes

Rhodium­(II) azavinyl carbenes, conveniently generated from 1-sulfonyl-1,2,3-triazoles, undergo a facile, mild, and convergent formal 1,3-insertion into N–H and O–H bonds of primary and secondary amides, various alcohols, and carboxylic acids to afford a wide range of vicinally bisfunctionalized (<i>Z</i>)-olefins with perfect regio- and stereoselectivity. Utilizing the distinctive functionality installed through these reactions, a number of subsequent rearrangements and cyclizations expand the repertoire of valuable organic building blocks constructed by reactions of transition-metal carbene complexes, including α-allenyl ketones and amino-substituted heterocycles

Stereoselective 1,3-Insertions of Rhodium(II) Azavinyl Carbenes

Rhodium­(II) azavinyl carbenes, conveniently generated from 1-sulfonyl-1,2,3-triazoles, undergo a facile, mild, and convergent formal 1,3-insertion into N–H and O–H bonds of primary and secondary amides, various alcohols, and carboxylic acids to afford a wide range of vicinally bisfunctionalized (<i>Z</i>)-olefins with perfect regio- and stereoselectivity. Utilizing the distinctive functionality installed through these reactions, a number of subsequent rearrangements and cyclizations expand the repertoire of valuable organic building blocks constructed by reactions of transition-metal carbene complexes, including α-allenyl ketones and amino-substituted heterocycles

Stereoselective 1,3-Insertions of Rhodium(II) Azavinyl Carbenes

Rhodium­(II) azavinyl carbenes, conveniently generated from 1-sulfonyl-1,2,3-triazoles, undergo a facile, mild, and convergent formal 1,3-insertion into N–H and O–H bonds of primary and secondary amides, various alcohols, and carboxylic acids to afford a wide range of vicinally bisfunctionalized (<i>Z</i>)-olefins with perfect regio- and stereoselectivity. Utilizing the distinctive functionality installed through these reactions, a number of subsequent rearrangements and cyclizations expand the repertoire of valuable organic building blocks constructed by reactions of transition-metal carbene complexes, including α-allenyl ketones and amino-substituted heterocycles