Synthesis of Indenes by Intramolecular anti-Hydroarylation of Propargylarenes

Transition-metal-catalyzed C–H allylation reactions

“…Transmuted allyl sources have evolved as alternatives of pre-functionalized allyl coupling partners. [89][90][91][92] These allyl reagents are generally olefin derivatives, which generate allyl motifs upon reaction under optimal conditions. Unlike previous cases,…”

Palladium Catalysis: Dependence of the Efficiency of C−C Bond Formation on Carboxylate Ligand and Alkali Metal Carboxylate or Carboxylic Acid Additive. Part B: The Hydro(hetero)arylation, Hydroalkenylation and Hydroalkylation Reactions

“…The Pd 0 /acid-catalyzed CÀ H bond activation has been used for intramolecular hydroarylation of -2-aryloxybut-1-en-3-yne of Scheme 5a using AcOH or t-BuCO 2 H, no more than 8% yield being obtained with HCO 2 H and CF 3 CO 2 H, [22,23] -aryloxyethynyl silane of Scheme 5b using t-BuCO 2 H for a quantitative yield, AcOH, CF 3 CO 2 H and ArCO 2 H giving no more than 17% yield, [24] -1-aryloxy-3-arylprop-1-yne of Scheme 5c using t-BuCO 2 H. [25] DFT calculations on the synthesis of benzosiloles have clarified the mechanism initially proposed [24] (Scheme 5d). [26] The Gibbs free energies of two catalytic cycles starting with LPd(t-BuCO 2 H) have been calculated.…”

“…using AcOH or t ‐BuCO 2 H, no more than 8% yield being obtained with HCO 2 H and CF 3 CO 2 H, [22,23] …”

“… 2‐aryloxybut‐1‐en‐3‐yne of Scheme 5ausing AcOH or t ‐BuCO 2 H, no more than 8% yield being obtained with HCO 2 H and CF 3 CO 2 H, [22,23] aryloxyethynyl silane of Scheme 5b using t ‐BuCO 2 H for a quantitative yield, AcOH, CF 3 CO 2 H and ArCO 2 H giving no more than 17% yield, [24] 1‐aryloxy‐3‐arylprop‐1‐yne of Scheme 5c using t ‐BuCO 2 H [25] …”

Access to Substituted Indenol Ethers via a Regioselective Intermolecular Carbopalladation Cascade

“…Intercepted Pd-vinyl adducts of alkyne carbopalladation reactions allow for access to diverse, highly functionalized products. Variations of this reaction are popular owing to the ability to build up molecular complexity and that the transformation is robust enough for wide ranging applications including complex total syntheses. − While many interesting examples within this class of reactions involve intramolecular alkyne carbopalladation, , where issues of regioselectivity are not prevalent, the directional control of migratory insertion is certainly a challenge for reactions that involve an intermolecular alkyne carbopalladation step. As a result, many examples involving intermolecular alkyne carbopalladation report only symmetrically substituted alkynes or limited examples of unsymmetrically substituted alkynes, , often with incomplete regioselectivity.…”