Silanes in organic syuthesis. 11. Regiocontrolled synthesis of α-hydroxymethylated (trimethylsilyl)allenes

Preparation of Organoaluminum Reagents from Propargylic Bromides and Aluminum Activated by PbCl2 and Their Regio‐ and Diastereoselective Addition to Carbonyl Derivatives

“…Thus, after an addition reaction to carbonyl derivatives, the allenic alcohols of type 5 are produced as single products in most cases (Table 2). Thus, the organoaluminum species generated from 1‐bromo‐2‐nonyne ( 1 b ; R=hexyl (Hex)) and (trimethylsilyl)propargyl bromide ( 1 c ; R=TMS)9a reacted with various aromatic and aliphatic ketones affording the allenic alcohols 5 as single isomers (Table 2, entries 1–4 and 6–11). No homopropargylic alcohols were observed in all of these cases.…”

Silicon-Mediated Organic Synthesis

“…The trialkylsilyl group serves to silicon-substituted ylide 64 undergoes conjugate addition to enones to give silylcyclopropanes (61). The organometallic produced by reaction of (trimethylsilyl)propargyl bromide with aluminum amalgam condenses with carbonyl compounds to give allenic products 65 (62).…”

A Computational Investigation of the Ligand-Controlled Cu-Catalyzed Site-Selective Propargylation and Allenylation of Carbonyl Compounds

“…1 The corresponding propargylation 2 and allenylation 3 reactions have attracted considerable attention, as the functionality in the resulting allenyl and propargyl carbinols is useful for further structural modification. 4 To meet demand, various methods for the direct allenylation of carbonyl compounds have been reported, including those based on B, 5 Al, 6 Si, 7 Cr, 8 Zn, 9 and other Lewis acids 10 with propargyl species. In addition, several systems for the site-selective propargylation of carbonyl systems have been reported.…”