Application of Pauson–Khand reaction in the total synthesis of terpenes

Abstract

The Pauson–Khand reaction (PKR) is a formal [2 + 2 + 1] cycloaddition involving an alkyne, an alkene and carbon monoxide mediated by a hexacarbonyldicobaltalkyne complex to yield cyclopentenones in a single step.

Recent advances in the syntheses of guaianolides

“…In 2019, Maimone and co-workers 13 a documented the evolution of a chiral pool-based synthetic program (Schemes 1–3) aimed at accessing an assortment of guaianolides based mainly on diastereoselective allylation to construct the central 7-membered ring. Toward the synthesis of sinodielide A, the chiral pool linalool 15 was esterified to 17 , which was used for the Pauson–Khand (PK) 14 reaction resulting in the strained bicyclic lactone 18 with the correct C-1 and C-10 chirality. The latter by reduction, allylic chlorination and oxidation gave the intermediate aldehyde 19 .…”

An Overview of Catalytic Carbonylative Double Cyclization Reactions

“…A general approach leading to carbonylative double cyclization is the intramolecular Pauson-Khand reaction starting from suitable diene or enyne substrates. Since several excellent reviews have been published on this reaction [44][45][46], even in the most recent literature [47][48][49], this process will not be treated here; however, a particularly striking The gaseous CO-free conditions elaborated by the Gracza group for the carbonylation of 4-ene-1,3-diols, involving the use of liquid [Fe(CO) 5 ] as an in situ CO source (Scheme 6), have also been successfully employed by the same research team in the Pd(II)-catalyzed carboylative double cyclization of N-protected 5-aminopent-1-en-3-ols, as in Scheme 13 [34]. The gaseous CO-free conditions elaborated by the Gracza group for the carbonylation of 4-ene-1,3-diols, involving the use of liquid [Fe(CO)5] as an in situ CO source (Scheme 6), have also been successfully employed by the same research team in the Pd(II)catalyzed carboylative double cyclization of N-protected 5-aminopent-1-en-3-ols, as in Scheme 13 [34].…”

“…A general approach leading to carbonylative double cyclization is the intramolecular Pauson-Khand reaction starting from suitable diene or enyne substrates. Since several excellent reviews have been published on this reaction [44][45][46], even in the most recent literature [47][48][49], this process will not be treated here; however, a particularly striking Scheme 13. Carbonylative double cyclization of tert-butyl (3-hydroxypent-4-en-1-yl)carbamate using [Fe(CO) 5 ] as in situ CO source [34].…”

“…A general approach leading to carbonylative double cyclization is the intramolecular Pauson-Khand reaction starting from suitable diene or enyne substrates. Since several excellent reviews have been published on this reaction [44][45][46], even in the most recent literature [47][48][49], this process will not be treated here; however, a particularly striking A general approach leading to carbonylative double cyclization is the intramolecular Pauson-Khand reaction starting from suitable diene or enyne substrates. Since several excellent reviews have been published on this reaction [44][45][46], even in the most recent literature [47][48][49], this process will not be treated here; however, a particularly striking example in Scheme 15 gives the reader an idea of the powerfulness of this synthetic method for constructing complex carbonylated polycyclic compounds [50].…”

A dinickel-catalyzed three-component cycloaddition of vinylidenes

“…[2 + 2 + 1]-Cycloadditions provide some of the most direct routes to five-membered rings and feature in numerous total syntheses of polycyclic natural products. 1 The Pauson–Khand reaction is the prototypical example in this class of cycloadditions and uses Co 2 (CO) 8 to mediate the coupling of an alkyne, an alkene, and CO (Fig. 1a).…”