FeCl3-catalyzed tandem Prins and Friedel–Crafts cyclization: a highly diastereoselective route to polycyclic ring structures

Abstract

Catalytic FeCl3 in the presence of 4Å molecular sieves has been shown to effect highly diastereoselective tandem Prins and Friedel-Crafts cyclization of substituted (E/Z)-6-phenylhex-3-en-1-ol and a variety of aldehydes to provide a range of polycyclic compounds in good to excellent yields. The reaction of an enantioenriched alcohol with an aldehyde provided the cyclization product without loss of optical activity. Furthermore, a Lewis acid catalyzed ring opening resulted in functionalized tetralin derivatives with multiple chiral centers.

MWW-type zeolite nanostructures for a one-pot three-component Prins–Friedel–Crafts reaction

“…12–15 This reaction involves Prins cyclization via interaction of a carbonyl compound and a homoallylic alcohol with the formation of an oxocarbenium ion that undergoes an intramolecular π-bond attack to construct a new carbon–carbon bond with a subsequent Friedel–Crafts alkylation with an arene nucleophile. 12,15 As an alternative route, an acid-catalyzed intramolecular (or tandem) Prins–Friedel–Crafts reaction of a homoallylic alcohol appended to a nucleophile with a carbonyl compound also allows one to obtain 4-aryltetrahydropyrans, 16–19 but this methodology is more complex as it requires additional synthesis steps to modify the substrate molecule.…”

The Application of 4Å Molecular Sieves in Organic Chemical Syntheses: An Overview

“…In 2011, Bhattacharya et al published the FeCl 3 catalysed one-pot, four-component condensation of diamines 13, acetone (14a) and phosphinate (15) in the presence of MS 4A, providing benzodiazepinyl phosphonates (BDPs) 16 with high yield (Scheme 4). 11 The water generated during the initial imine formation can decompose or deactivate the catalyst, which can be avoided by the use of MS 4A.…”

“…In 2014, Ghosh and co-workers developed the FeCl 3 catalysed Prins-Friedel-Crafts cascade cyclisation of (E)-and (Z)-6-phenylhex-3-en-1-ols with different aliphatic and aromatic aldehydes 24 in the presence of MS 4A. 15 The application of molecular sieves resulted in shorter reaction times and slightly better yields.…”

Modulating Prins Cyclization versus Tandem Prins Processes for the Synthesis of Hexahydro‐1H‐pyrano[3,4‐c]chromenes

“…On the other hand, the use of homoallylic alcohols with a tethered nucleophile allows reaching further molecular complexity, with the formation of polycycles via Prins cascade sequences, [4] even in an enantioselective fashion [4d] . We have already reported the synthesis of hexahydro‐1 H ‐pyrano[3,4‐ c ]quinolones via a tandem Prins/Friedel‐Crafts process starting from 5‐arylamino‐pentenols in the presence of BF 3 ⋅Et 2 O, [5] and a FeCl 3 ‐catalysed tandem Prins/Friedel‐Crafts has also been reported starting from 6‐phenyl‐hexenols to deliver hexahydro‐1 H ‐benzo[ f ]isochromenes [6] . An elegant method has been reported for the synthesis of chromenes using In(OTf) 3 with ionic liquids [7a] .…”