Regio- and Stereoselective Synthesis of 1,2,3-Trisubstituted Indanes from Diarylmethanols and Allylamides through Iron(III) Chloride Hexahydrate

Acid-Mediated Domino Cyclization of ortho-Formyl Cinnamate Esters: Synthesis of Substituted Indene/Indane Esters and Indeno[a]indenones

A Bro̷nsted acid-driven protocol to access substituted monoarylindene esters, biarylindane esters, and indeno[a]indenones from simple ortho-formylcinnamate esters and external arenes has been revealed. Remarkably, this single-pot process enabled the construction of two, three, and four new C-C bonds in building monoarylindene esters, biarylindane esters, and indeno[a]indenones, respectively, under metal-free and mild reaction parameters via triggering the inactive cinnamate ester moiety. In addition, the present strategy is investigated with widespread substrate scope.

Photoacid-Enabled Synthesis of Indanes via Formal [3 + 2] Cycloaddition of Benzyl Alcohols with Olefins

An environmentally friendly and highly diastereoselective method for synthesizing indanes has been developed via a metastable-state photoacid system containing catalytic protonated merocyanine (MEH). Under visible-light irradiation, MEH yields a metastable spiro structure and liberated protons, which facilitates the formation of carbocations from benzyl alcohols, thus delivering diverse molecules in the presence of various nucleophiles. Mainly, a variety of indanes could be easily obtained from benzyl alcohols and olefins, and water is the only byproduct.

Acid-Mediated Decarboxylative C–H Coupling between Arenes and O-Allyl Carbamates

Treatment of O-allyl N-tosyl carbamates with aromatic compounds in the presence of Cu(OTf)2 or TMSOTf as promoters, affords N-substituted 1-arylpropan-2-amines, 1,2-diarylpropanes, 1,1-diarylpropanes, or indanes, depending on the nature of the...

Design, Synthesis and Late-Stage Modification of Indane-Based Peptides via [2+2+2] Cyclotrimerization

Here, we prepared several dipeptides containing 2-aminoindane-2-carboxylic acid (Aic) and carried out further synthetic transformations. Synthesis and purification of modified peptides by using [2+2+2] cyclotrimerization is a challenging task. We are able to modify the unusual amino acids and peptide derivatives by late-stage incorporation of benzylhalo functionality. To incorporate benzylhalo moiety we used [2+2+2] cyclotrimerization in the presence of Mo(CO)₆ . These halo derivatives are potential substrates for further modification by Sonogashira reaction, Suzuki-Miyaura cross-coupling, sultine formation, and the Diels-Alder reaction sequence.

Spectroscopic characterisation of centropolyindanes

A highly promising class of three-dimensional polyaromatic hydrocarbons comprises the centropolyindanes. The characteristic feature of these compounds is the mutual fusion of several molecules of indane along the saturated C-C bonds of their cyclopentane rings. Among the polycyclic aromatic hydrocarbons, the centropolyindanes are special because of the saturated core of sp3-hybridised carbon atoms embedded in a three-dimensional environment of aromatic building blocks. While the centropolyindanes and their numerous derivatives have been studied in detail by NMR spectroscopy, mass spectrometry and X-ray diffraction, investigation of their vibrational features, and especially those of the neopentane core present in most cases, have not been performed so far. In the present paper, we report the first systematic study of a set of centropolyindanes by vibrational spectroscopy, using inelastic neutron scattering (INS), infrared and Raman spectroscopies.

Triflimide-catalyzed allylsilane annulations of benzylic alcohols for the divergent synthesis of indanes and tetralins

The development of a triflimide-catalyzed annulation of benzylic alcohols with allylsilanes for the synthesis of indane or tetralin structures is reported. In this fragment coupling reaction, complexity is built rapidly from readily available starting materials to yield diverse sets of products with up to three contiguous stereocenters. Indanes or tetralins can be generated from common precursors depending on the structure of the allylsilane reagent used. The concise synthesis of several lignan natural products highlights the utility of this newly devised methodology.

Iron(iii) chloride hexahydrate-promoted selective hydroxylation and chlorination of benzyl ketone derivatives for the construction of hetero-quaternary scaffolds

A tunable α-hydroxylation/α-chlorination of benzylketone derivatives for the construction of hetero-quaternary units has been developed by iron(iii) chloride hexahydrate-mediated selective transformations.