A cationic rhodium(I)/BINAP [2,2′-bis(diphenylphosphino)-1,1′-binaphthyl] complex is capable of catalyzing the [2+2+2] cycloaddition–aromatization of 1,6-diynes with cyclic enol ethers (2,3-dihydrofuran and dihydropyran) at room temperature to produce the corresponding aryl alkanol derivatives in good yields. In this process, a conjugated dihydrofuran showed a significantly higher reactivity than a nonconjugated one.

It has been established that a cationic rhodium(I)/binap complex catalyzes the cross-cyclotrimerization of two molecules of a monosubstituted allene with one molecule of a functionalized alkyne to give 3,6-dialkylidenecyclohex-1-enes. In contrast, the reactions involving di- or trisubstituted allenes and/or unfunctionalized alkynes afforded cross-dimerization products, substituted dendralenes, through β-hydrogen elimination from the corresponding rhodacycles.

It has been established that a cationic rhodium(I)/binap complex catalyzes the cross-cyclotrimerization of two molecules of a monosubstituted allene with one molecule of a functionalized alkyne to give 3,6-dialkylidenecyclohex-1-enes. In contrast, the reactions involving di- or trisubstituted allenes and/or unfunctionalized alkynes afforded cross-dimerization products, substituted dendralenes, through β-hydrogen elimination from the corresponding rhodacycles.

The enantioselective synthesis of an aza[10]helicene, possessing two pyridone units, has been achieved by the gold-catalyzed intramolecular quadruple hydroarylation of a tetrayne. This aza[10]helicene was successfully converted into a fully aromatic aza[10]helicene, possessing two pyridine units. Structure–photophysical and chiroptical properties relationship in a series of azahelicene isomers has also been disclosed.

The convenient and atom-economical synthesis of substituted bicyclic pyridylphosphonates has been achieved by the cationic rhodium(I)/H₈-binap-complex-catalyzed [2+2+2] cycloaddition of 1,6- and 1,7-diynes with diethyl phosphorocyanidate. These reactions may proceed via an azarhodacyclopentadiene intermediate in addition to the rhodacyclopentadiene intermediate.

A 1,1′-bitriphenylene-based sila[7]helicene was synthesized with a high ee value by enantioselective double [2+2+2] cycloaddition of a biaryl-linked tetrayne with a silicon-linked bis(propargylic alcohol) as a key step. This sila[7]helicene exhibited a high tolerance toward racemization, which could be explained by the X-ray crystal structure analysis. With respect to the photophysical properties, this sila[7]helicene exhibited a relatively high fluorescence quantum yield and circularly polarized luminescence activity.

A cationic gold(I)/axially chiral biaryl bis(phosphine) complex has been employed to catalyze the asymmetric dearomatization reactions of 1-aminonaphthalene derivatives through a C–C bond-forming reaction with electron-rich heterocycles as the nucleophiles. These reactions afford pentacyclic heterocycles in good yields with moderate enantiomeric excess (ee) values.

The concise synthesis of C₃-symmetrical [12]CPP-hexacarboxylate has been achieved through macrocyclization by the rhodium-catalyzed intermolecular cross-cyclotrimerization and subsequent reductive aromatization. C₃-Symmetrical functionalization of CPP with highly polar alkoxycarbonyl groups enabled the structurally uniform nanotube assembly in the crystalline state through multiple hydrogen-bonding interactions giving a dimer followed by one-dimensional stacking.

It has been established that a cationic rhodium(I)/H₈-binap complex catalyzes the [3+2+2] cycloaddition of 1,6-diynes with cyclopropylideneacetamides to produce cycloheptadiene derivatives through cleavage of cyclopropane rings. In contrast, a cationic rhodium(I)/(S)-binap complex catalyzes the enantioselective [2+2+2] cycloaddition of terminal alkynes, acetylenedicarboxylates, and cyclopropylideneacetamides to produce spiro-cyclohexadiene derivatives which retain the cyclopropane rings.

It has been established that a cationic rhodium(I)/H₈-binap complex catalyzes the [3+2+2] cycloaddition of 1,6-diynes with cyclopropylideneacetamides to produce cycloheptadiene derivatives through cleavage of cyclopropane rings. In contrast, a cationic rhodium(I)/(S)-binap complex catalyzes the enantioselective [2+2+2] cycloaddition of terminal alkynes, acetylenedicarboxylates, and cyclopropylideneacetamides to produce spiro-cyclohexadiene derivatives which retain the cyclopropane rings.

The oxidative olefination of sp² CH bonds of anilides with both activated and unactivated alkenes using an (electron-deficient η⁵-cyclopentadienyl)rhodium(III) complex is reported. In contrast to reactions using this electron-deficient rhodium(III) catalyst, [Cp*RhCl₂]₂ showed no activity against olefination with unactivated alkenes. In addition, the deuterium kinetic isotope effect (DKIE) study revealed that the CH bond cleavage step is thought to be the turnover-limiting step.

The enantioselective synthesis of completely ortho-fused [9]- and [11]helicene-like molecules has been achieved through a rhodium-mediated, intramolecular, double [2+2+2] cycloaddition of phenol- or 2-naphthol-linked hexaynes. Crystal structures and photophysical properties of these [9]- and [11]helicene-like molecules have also been disclosed.

The enantioselective synthesis of completely ortho-fused [9]- and [11]helicene-like molecules has been achieved through a rhodium-mediated, intramolecular, double [2+2+2] cycloaddition of phenol- or 2-naphthol-linked hexaynes. Crystal structures and photophysical properties of these [9]- and [11]helicene-like molecules have also been disclosed.