Photocycloaddition of Biscyclopropyl Alkenes to C60: An Unprecedented Approach toward cis-1 Tricyclic-Fused Fullerenes

Copper-Mediated Radical-Induced Ring-Opening Relay Cascade Carboannulation Reaction of [60]Fullerene with Cyclobutanone Oxime Esters: Access to [60]Fullerene-Fused Cyclopentanes

An unexpected copper-mediated radical-induced ring-opening relay cascade carboannulation reaction of [60]fullerene with cyclobutanone oxime esters is presented for the preparation of various Cl-/Br-incorporated [60]fullerene-fused cyclopentanes. The unique relay cascade transformation uses inexpensive copper salts as promoters and halogen sources and features simple redox-neutral conditions and a broad substrate scope, providing a practical access to a class of novel five-membered carbocycle-fused fullerenes.

Direct Trideuteromethylation of Sulfenate Anions Generated In Situ from β-Sulfinyl Esters: An Access to Trideuteromethyl Sulfoxides

Deuterated organic molecules have immense value in the pharmaceutical industry. Here, we present a synthetic strategy for direct trideuteromethylation of sulfenate ions derived in situ from β-sulfinyl esters in the presence of a base utilizing inexpensive and abundant CD₃OTs as the electrophilic trideuteromethylating agent. This protocol provides straightforward access to an array of trideuteromethyl sulfoxides in yields of 75-92% with a high degree of deuteration. The ensuing trideuteromethyl sulfoxide can be readily modified into trideuteromethyl sulfone and sulfoximine.

Intramolecular Photoreactions of 9-Cyanophenanthrene-Linked Arylcyclopropanes

With the aim of developing efficient and useful processes for the preparation of polycyclic organic compounds, intramolecular [3 + 2] photoreactions of 9-cyanophenanthrene-linked arylcyclopropanes were investigated. Photoreactions of 6a,b, which contain respective p-methoxyphenylcyclopropane and phenylcyclopropane moieties, form the intramolecular [3 + 2] photocycloadducts, endo- and exo-7a,b, along with the dihydroisochroman derivatives, cis- and trans-8a,b. The efficiency of the photoreaction of 6a is higher when benzene rather than acetonitrile is used as a solvent. Interestingly, this solvent effect is reversed in the photoreaction of 6b, where the efficiency is higher in acetonitrile than that in benzene. On the basis of the observed effects of substituents and solvents, fluorescence emission from intramolecular exciplexes, and ΔGs for intramolecular single electron transfer (SET), we propose that the photoreactions proceed through pathways involving the initial formation of singlet intramolecular exciplexes and/or SET between the excited 9-cyanophenanthrene and the ground-state arylcyclopropane moieties.

Unexpected isomerism in cis-2 bis(pyrrolidino)[60]fullerene diastereomers

Similar yet different: A one-step regio- and diastereoselective synthesis of three new bis(pyrrolidine)[60]fullerenes, one cis-1 and two unprecedented cis-2 diastereoisomers, is reported. The compounds are easily purified using simple chromatographic techniques, and were fully characterized by spectroscopic techniques and X-ray crystallography. A mechanism for the isomeric conversion observed is proposed.