Palladium-Catalyzed Regioselective Synthesis of 2-SF5-Indenols and Further Derivatizations

A palladium-catalyzed synthesis of 2-SF₅-indenols has been developed by reacting commercially available boronic acid derivatives and readily accessible SF₅-alkynes. The present methodology is fully regioselective thanks to the intrinsic polarization of SF₅-alkynes. A selection of downstream functionalizations has been performed to highlight the versatility of 2-SF₅-indenols and indenones as platforms for the design of more complex SF₅-containing molecules.     

Palladium-Catalyzed Regioselective Synthesis of 3-Arylindoles from N-Ts-Anilines and Styrenes

A Pd-catalyzed intermolecular oxidative annulation between N-Ts-anilines and styrenes was developed. This method offers a straightforward and robust approach to a wide range of 3-arylindoles using readily available starting materials with good functional-group tolerance and high regioselectivity and efficiency. Further elaboration of the products obtained from this process provided access to highly functionalized and structurally diverse indoles, for example, 3-(indol-3-yl)carbazoles, 1,9-dihydropyrrolo-[2,3-b]carbazoles, and 3′-aryl-3,5′-biindoles.     

Palladium-Catalyzed Enantio- and Regioselective Ring-Opening Hydrophosphinylation of Methylenecyclopropanes

Transition metal-catalyzed hydrofunctionalization of methylenecyclopropanes (MCPs) has presented a considerable challenge due to the difficult manipulation of regioselectivity and complicated reaction patterns. Herein, we report a straightforward Pd-catalyzed ring-opening hydrophosphinylation reaction of MCPs via highly selective C−C bond cleavage. This method allows for rapid and efficient access to a wide range of chiral allylic phosphine oxides in good yields and high enantioselectivities. Additionally, density functional theory (DFT) calculations were performed to elucidate the reaction mechanism and the origin of enantioselectivity.     

Regioselective Palladium-Catalyzed Cross-Coupling Reactions of 2,4,7-Trichloroquinazoline

The regioselective palladium-catalyzed cross-coupling reactions of 2,4,7-trichloroquinazoline with various aryl- and heteroarylboronic acids are reported. An efficient, sequential strategy was developed that provides access to novel, functionalized heterocycles.     

Palladium-Catalyzed cross-Benzannulation of Aminoenynes with Diynes. Highly Regioselective Synthesis of Polysubstituted Anilines

Polysubstituted anilines were prepared by the palladium-catalyzed cross-benzannulation of conjugated aminoenynes 1-4 with diynes 8. The reaction proceeded in a highly regioselective manner under mild conditions, and the anilines were obtained as single regioisomers. Our method complements the well-known precedures for the preparation of polysubstituted anilines which are widely used in organic synthesis.     

Palladium-Catalyzed Regioselective peri- and ortho-Halogenation of 1-Naphthaldehydes: Application to the Synthesis of Polycyclic Natural Product Skeletons

Herein, a regioselective bromination or chlorination reaction of 1-naphthaldehydes is described. Without additive, the palladium-catalyzed C−H halogenation showed a C8-regioselectivity, whereas the formation of an aromatic imine intermediate allowed a switch to a C2-reactivity. Mechanistic studies and DFT calculations were performed to explain the regioselectivity and the synthesized halogenated products were used as key building blocks to access polycyclic natural product skeletons.     

Palladium-Catalyzed Synthesis of Tetrahydrocarbazoles

The synthesis of tetrahydrocarbazoles from bromoenaminones derived from β-diketones is described. The reaction proceeds by intramolecular cyclization of bromoenaminones involving arylpalladium complexes.     

Palladium-Catalyzed Cyclocarbonylation of 2-Halobenzaldehyde and Hydrazines: A Facile Synthesis of 2-Aminoisoindolin-1-ones

An efficient procedure for the synthesis of 2‐aminoisoindolin‐1‐ones via a palladium‐catalyzed three‐component reaction of 2‐halobenzaldehydes, hydrazines and carbon monoxide is reported. This cyclocarbonylation process can be performed smoothly under 1 atmospheric pressure of carbon monoxide to afford 2‐aminoisoindolin‐1‐ones in moderate to excellent yields.     

Regioselective Synthesis of Two Novel 2-geranyloxyacetophenones

The phenols containing geranyl units¹ are a large group of interesting natural products exhibited many physiological actions as antiflammatory, antibacterial and antioxidative activities². Two novel acetophenones 1 and 2 were recently isolated from the fruits of Evodia merrillii, a small folk medicinal tree widely distributed in Taiwan³. Their structures were elucidated as 2-(1'-geranyl)-4,6-dihydroxyacetophenone 1 and 2-(1'-geranyloxy)-2,6,α-trihydroxyacetophenone 2 by means of spectroscopic data. So far as we know, the total synthesis of them have not been reported yet. Herein, we wish to report the first total synthesis of 1 and 2,starting from 2,4,6-trihydroxyacetophenone.     

Palladium-Catalyzed Direct C2-and Further C7-Acylation of Indoles with Aldehydes

The palladium‐catalyzed direct C2‐ and further C7‐acylation of indoles with aldehydes have been developed. This method provides a convenient pathway toward a variety of mono‐ and diacylated indoles.     

Palladium-Catalyzed Synthesis of 4-Aminoquinazolines from Amide Oxime Ethers and 2-Iodobenzonitrile

Russian Journal of General Chemistry - 4-Substituted O-benzyl benzamide oximes reacted with 2-iodobenzonitrile in the presence of 0.1 mol % of [Pd2(dba)3], 0.2 mol % of XantPhos, and 1.5 equiv of...     

Synthesis of Spiroindenyl-2-Oxindoles through Palladium-Catalyzed Spirocyclization of 2-Bromoarylamides and Vinyl Bromides

An expeditious approach to the construction of spiroindenyl-2-oxindoles was developed via a palladium-catalyzed spirocyclization reaction of 2-bromoarylamides with vinyl bromides. The reaction formed spiropalladacycles as the intermediates via carbopalladation and the C–H functionalization of 2-bromoarylamides. The spiropalladacycles reacted with vinyl bromides to form spiroindenyl-2-oxindoles. A Heck process rather than vinylic C–H functionalization was involved in the reaction.