Jacques Pornet

Jacques Pornet; B. Randrianoelina; L. Miginiac

Abstract The preparation of organo-magnesium, -zinc and -aluminum compounds from several primary α-allenic bromides, and their structures, stabilities and reactivities towards various halides are described. The organomagnesium compounds react readily with halides in the presence of Li2CuCl4.

Jacques Pornet

Resume Propargyltrimethylsilane reacts with carbonyi compounds to produce chloroprenic derivatives in the presence of titanium tetrachloride.

Jacques Pornet; D. Damour; L. Miginiac

Abstract The ω-silyloxypropargyltrimethylsilanes regiospecifically react with aliphatic and aromatic aldehydes to lead to vinylidene oxygen-containing heterocycles,such as 3-vinylidene oxolanes, oxanes, oxepanes and oxocanes.

Jacques Pornet; D. Damour; L. Miginiac

Abstract Protodesilylation of varied propargyltrimethylsilanes, using boron trifluorideacetic acid as reagent, give regiospecifically terminal allenes with very good yields. Yet, particular ω-functional propargyltrimethylsilanes may lead to vinylsilanes resulting from a ring-closing cyclisation reaction.

Jacques Pornet; D. Mesnard; L. Miginiac

Abstract 1,3-bis(trimethylsilyl)-1-alkynes may be obtained from trimethylsilyl propargylsilanes by metallation with n-butyllithium following by reaction with trimethylsilylchloride; these silanes easily react with acetals, in the presence of titanium tetrachloride, to produce α-functional allenyltrimethylsilanes.

Jacques Pornet

Abstract α-and α,γ-unsaturated silanes undergo titanium tetrachloride-induced alkylation of acetals.

Jacques Pornet

Resume Propargyltrimethylsilane reacts with carbonyl compounds to produce α-allenic alcohols in the presence of tetra-n-butylammonium fluoride.

Jacques Pornet; N'Banéyapé Kolani

Abstract 1,4-Bistrimethylsilyl-2-butyne reacts with acetals, in the presence of titanium tetrachloride, to produce either functional α-allenyltrimethylsilanes (monoreaction) or difunctional conjugated dienes (direaction).

Jacques Pornet; D. Damour; B. Randrianoelina; L. Miginiac

Abstract The α-silyloxypropargyltrimethylsilanes regiospecifically react with aliphatic aldehydes to lead to alkyl-substituted 5-vinylidene-1,3-dioxanes, in a one-pot reaction.

Jacques Pornet; B. Randrianoelina

Resume 1-trimethylsilyl 2-butyne reacts with carbonyl compounds in the presence of titanium tetrachloride or tetra-n-butylammonium fluoride, to produce mainly α-allenic alcohols; with titanium tetrachloride, it is also possible to obtain chloroprenic derivatives only.