Synthesis and Characterization of Dithia[3.3](2,6)pyridinophane-Containing Polymers: Application to the Palladium-Catalyzed Heck Reaction

We synthesized zigzag polymers consisting of dithia[3.3](2,6)pyridinophane units that were flipped rapidly as a result of syn-[anti]-syn isomerization. Pyridinophane units were fixed in the syn form by complexation with palladium, and the resulting polymer complex exhibited a high catalytic activity for the Heck coupling reaction

Polymethylenes Containing [2.2]Paracyclophane in the Side Chain

Polymethylenes Containing [2.2]Paracyclophane in the Side Chai

Synthesis of Enantiopure P‑Stereogenic Diphosphacrowns using P‑Stereogenic Secondary Phosphines

A new synthetic route to enantiopure P-stereogenic benzodiphosphacrowns using a P-stereogenic secondary bisphosphine as the key building block is reported. Syntheses of the enantiomer and P-stereogenic crowns with various ring structures, as well as deboranation of the crown compounds and subsequent reaction with a platinum complex, are described

Synthesis of Enantiopure P‑Stereogenic Diphosphacrowns using P‑Stereogenic Secondary Phosphines

A new synthetic route to enantiopure P-stereogenic benzodiphosphacrowns using a P-stereogenic secondary bisphosphine as the key building block is reported. Syntheses of the enantiomer and P-stereogenic crowns with various ring structures, as well as deboranation of the crown compounds and subsequent reaction with a platinum complex, are described

Synthesis and Properties of [2.2]Paracyclophane-Layered Polymers

Synthesis and Properties of [2.2]Paracyclophane-Layered Polymer

A New Route to Cyclopentenones via Ruthenium-Catalyzed Carbonylative Cyclization of Allylic Carbonates with Alkenes

[RuCl2(CO)3]2/Et3N and (η3-C3H5)RuBr(CO)3/Et3N are highly effective catalyst systems for carbonylative cyclization of allylic carbonates with alkenes to give the corresponding cyclopentenones in high yields. For example, treatment of allyl methyl carbonate (1a) with 2-norbornene (2a) in the presence of a catalytic amount of [RuCl2(CO)3]2 (2.5 mol %) and Et3N (10 mol %) at 120 °C for 5 h under 3 atm of carbon monoxide gave the corresponding cyclopentenone, exo-4-methyltricyclo[5.2.1.02,6]dec-4-en-3-one (3a), in 80% yield with high stereoselectivity (exo 100%)

Ruthenium-Catalyzed Allylic Substitution of Cyclic Allyl Carbonates with Nucleophiles. Stereoselectivity and Scope of the Reaction

CpRuCl(cod)/NH4PF6 (Cp = cyclopentadienyl, cod = 1,5-cyclooctadiene) is an effective catalyst system for the allylic substitution of cyclic allyl carbonates with nucleophiles. This catalyst system enables the first investigation of the stereochemical course of the ruthenium-catalyzed allylic substitution reaction, in which the reaction proceeds with an overall retention of configuration. The stoichiometric reaction of trans-5-(methoxycarbonyl)cyclohex-2-enyl chloride with Cp*RuCl(cod) (Cp* = pentamethylcyclopentadienyl) gave the unexpected complex Cp*Ru(η6-C6H5CO2Me)+ by the rapid dehydrohalogenation/dehydrogenation of the desired Cp*RuCl2(η3-C6H8CO2Me) complex

Synthesis of Enantiopure P‑Stereogenic Diphosphacrowns using P‑Stereogenic Secondary Phosphines

A new synthetic route to enantiopure P-stereogenic benzodiphosphacrowns using a P-stereogenic secondary bisphosphine as the key building block is reported. Syntheses of the enantiomer and P-stereogenic crowns with various ring structures, as well as deboranation of the crown compounds and subsequent reaction with a platinum complex, are described

A One-Pot Synthesis and Functionalization of Polyynes

A one-pot synthesis and derivatization of diynes and triynes is reported. The polyyne framework is formed from a dibromoolefin precursor based on a carbenoid rearrangement, and the resulting Li−acetylide is then trapped in situ with an electrophile to provide functionalized di- and triynes. Alternatively, transmetalation of the Li−acetylide intermediate provides either the Zn− or Sn−acetylide, which then allows for the divergent preparation of diaryl polyynes or aryl ynones via palladium-catalyzed cross-coupling reactions

Ruthenium-Catalyzed Allylic Substitution of Cyclic Allyl Carbonates with Nucleophiles. Stereoselectivity and Scope of the Reaction

CpRuCl(cod)/NH4PF6 (Cp = cyclopentadienyl, cod = 1,5-cyclooctadiene) is an effective catalyst system for the allylic substitution of cyclic allyl carbonates with nucleophiles. This catalyst system enables the first investigation of the stereochemical course of the ruthenium-catalyzed allylic substitution reaction, in which the reaction proceeds with an overall retention of configuration. The stoichiometric reaction of trans-5-(methoxycarbonyl)cyclohex-2-enyl chloride with Cp*RuCl(cod) (Cp* = pentamethylcyclopentadienyl) gave the unexpected complex Cp*Ru(η6-C6H5CO2Me)+ by the rapid dehydrohalogenation/dehydrogenation of the desired Cp*RuCl2(η3-C6H8CO2Me) complex