Carboindation of Alkynes. Regio- and Stereoselective Allylation of Carbon-Carbon Triple Bonds of Alkynols by Allylic Indium Reagents

Indium Metal and Its Halides in Organic Synthesis

“…[6] Recently, a procedure has been reported for the allylation of alkynols using indium powder and allylic bromides in DMF at elevated temperature, leading to allylalkenols predominantly by anti Markovnikov addition. [7] However, the presence of a hydroxy functionality adjacent to the triple bond was found to be essential for facilitating this addition and thus the allylation of nonfunctionalized alkynes could only be accomplished in low yields (12Ϫ28%), even at higher temperatures. Moreover, hydroxy-protected alkynes could not be allylated at all.…”

“…Moreover, hydroxy-protected alkynes could not be allylated at all. [7] Nevertheless, the author's group has observed a very significant effect on the course of indium-mediated allylation reaction through a change of solvent and slight modification of the experimental conditions. [8] Thus, unactivated (non-functionalized and hydroxy-protected) alkynes have been found to undergo efficient allylation by Markovnikov addition simply by treating them with allyl bromide and indium metal in THF at room temperature (Scheme 1).…”

Ruthenium‐katalysierte Reaktionen – eine Schatzkiste für atomökonomische Umwandlungen

“…B. der formalen Synthese von (À)-Mycalamid A (190) (Schema 17). [148] In [158][159][160][161] eine Lewis-säurekatalysierte Addition von Allylsilanen oder Allylstannanen [162][163][164] oder auch eine Palladium-katalysierte Addition von Allylhalogeniden an Alkine. [165] 5.3.…”

Indium Metal and Its Halides in Organic Synthesis

“…Although the carbometallation of activated alkynes, such as alkynyl ketones, proceeds readily with various allylmetal compounds, [5] the carbometallation of unactivated alkynes is not so easy and only a few metals have been successfully employed for this purpose. [7] However, the presence of a hydroxy functionality adjacent to the triple bond was found to be essential for facilitating this addition and thus the allylation of nonfunctionalized alkynes could only be accomplished in low yields (12Ϫ28%), even at higher temperatures. [7] However, the presence of a hydroxy functionality adjacent to the triple bond was found to be essential for facilitating this addition and thus the allylation of nonfunctionalized alkynes could only be accomplished in low yields (12Ϫ28%), even at higher temperatures.…”

“…[6] Recently, a procedure has been reported for the allylation of alkynols using indium powder and allylic bromides in DMF at elevated temperature, leading to allylalkenols predominantly by anti Markovnikov addition. [7] Nevertheless, the author's group has observed a very significant effect on the course of indium-mediated allylation reaction through a change of solvent and slight modification of the experimental conditions. Moreover, hydroxy-protected alkynes could not be allylated at all.…”