Methodology for the Preparation of C1-Monoalkylated 1,2-Dihydro[C₇₀] Derivatives: Formation of the “Other” Regioisomer

Deprotonation of 1,2-C70H2 with TBAOH, followed by alkylation with methyl bromoacetate, results in formation of a C1-monoalkylated 1,2-dihydro-C70 derivative. The position of the alkyl group (C1) was established by NMR spectroscopy and comparison with literature spectra of C2-monoalkylated analogs. Presumably, C1-alkylation is the major process due to selective deprotonation of 1,2-C70H2 at C1. Substitution of benzyl bromide for methyl bromoacetate results in rapid dialkylation, unless the amount of base is carefully controlled, in which case C1-monobenzylation is the major process. This methodology for alkylation at C1 is complimentary to methods for the C2-monoalkylation of C70 with Zn and methyl bromoacetate

Monoalkylation of C₆₀ and C₇₀ with Zn and Active Alkyl Bromides

We report a convenient and simple solution-phase electron-transfer reaction of C60 with zinc and α-bromoacetonitrile, α-bromo acetate esters, allyl bromide, benzyl bromide and α-bromo ketones in DMF, with which different types of monoalkylated C60 derivatives can be prepared. When this method is employed with C70, 2-carbomethoxymethyl-1,2-dihydro[70]fullerene (isomer 5a) is produced as one of the two 1,2-monoalkylated C70 isomers, together with the first 5,6-monoalkylated C70 derivative

Monoalkylation of C₆₀ and C₇₀ with Zn and Active Alkyl Bromides

We report a convenient and simple solution-phase electron-transfer reaction of C60 with zinc and α-bromoacetonitrile, α-bromo acetate esters, allyl bromide, benzyl bromide and α-bromo ketones in DMF, with which different types of monoalkylated C60 derivatives can be prepared. When this method is employed with C70, 2-carbomethoxymethyl-1,2-dihydro[70]fullerene (isomer 5a) is produced as one of the two 1,2-monoalkylated C70 isomers, together with the first 5,6-monoalkylated C70 derivative

Lewis Acids Promoted Formal Intramolecular [3 + 2] Parallel and Cross-Cycloadditions of Cyclopropane 1,1-Diesters with Allenes

A novel Lewis acid promoted formal intramolecular [3 + 2] parallel/cross-cycloaddition of cyclopropane 1,1-diesters with allenes has been successfully developed, in which the two CC of allenes were involved respectively. This provides a general and efficient strategy for the construction of structurally diverse [4.3.0]nonane and [3.2.1]octane skeletons

Lewis Acid Catalyzed Ring-Opening Intramolecular Friedel−Crafts Alkylation of Methylenecyclopropane 1,1-Diesters

The first Friedel−Crafts reaction initiated by the direct generation of a carbocation at the C3 position of MCP 1,1-diesters through distal-bond cleavage was presented. The described method supplied a new synthetic strategy to prepare indene and hydronaphthalene derivatives in moderate to excellent yields under mild conditions

Lewis Acids Promoted Formal Intramolecular [3 + 2] Parallel and Cross-Cycloadditions of Cyclopropane 1,1-Diesters with Allenes

A novel Lewis acid promoted formal intramolecular [3 + 2] parallel/cross-cycloaddition of cyclopropane 1,1-diesters with allenes has been successfully developed, in which the two CC of allenes were involved respectively. This provides a general and efficient strategy for the construction of structurally diverse [4.3.0]nonane and [3.2.1]octane skeletons

Lewis Acid Catalyzed Ring-Opening Intramolecular Friedel−Crafts Alkylation of Methylenecyclopropane 1,1-Diesters

The first Friedel−Crafts reaction initiated by the direct generation of a carbocation at the C3 position of MCP 1,1-diesters through distal-bond cleavage was presented. The described method supplied a new synthetic strategy to prepare indene and hydronaphthalene derivatives in moderate to excellent yields under mild conditions

Lewis Acid Catalyzed Ring-Opening Intramolecular Friedel−Crafts Alkylation of Methylenecyclopropane 1,1-Diesters

The first Friedel−Crafts reaction initiated by the direct generation of a carbocation at the C3 position of MCP 1,1-diesters through distal-bond cleavage was presented. The described method supplied a new synthetic strategy to prepare indene and hydronaphthalene derivatives in moderate to excellent yields under mild conditions

N-Heterocyclic Carbene-Catalyzed Domino Ring-Opening/Redox Amidation/Cyclization Reactions of Formylcyclopropane 1,1-Diesters: Direct Construction of a 6−5−6 Tricyclic Hydropyrido[1,2-<i>a</i>]indole Skeleton

Catalyzed by N-heterocyclic carbenes (NHCs), domino ring-opening/redox amidation/cyclization reactions of the readily available formylcyclopropane 1,1-diesters with 2-chloro-1H-indole-3-carboaldehydes were reported. This methodology provides an efficient and direct construction of a 6−5−6 tricyclic hydropyrido[1,2-a]indole skeleton, which can be potentially applied for the synthesis of several types of polycyclic indole alkaloids

TfOH-Catalyzed Formal [3 + 2] Cycloaddition of Cyclopropane 1,1-Diesters with Nitriles

A triflic acid-catalyzed formal [3 + 2] cycloaddition of cyclopropane 1,1-diesters with nitriles was developed. This reaction was expeditious, and the scope of the substituents in both cyclopropanes and nitriles was broad. This supplies an efficient and practical method for the synthesis of 1-pyrrolines