Synthesis of Dithioacetals from Carbonyl Compounds and Thiols in the Presence of Polyphosphoric Acid Trimethylsilyl Ester (PPSE)
作者:Masa-aki Kakimoto、Takuya Seri、Yoshio Imai
DOI:10.1055/s-1987-27872
日期:——
Dithioacetals were synthesized from carbonyl compounds and thiols in the presence of polyphosphoric acid trimethylsilyl ester (PPSE) Aldehydes, Ketones, and trioxane could be used as carbonyl compounds, and aromatic, primary, secondary, and tertiary thiols were applicable in the present reaction. The reaction between cyclohexanone and t-butyl thiol afforded a mixture of corresponding dithioacetal and t-butylcyclohexenylsulfide.
only discuss symmetrical dithioacetals. Examples of mixed dithioacetals are scarce and no general method for the selective synthesis of these compounds exists. Herein, a synthetically simple general one‐step protocol was developed for the synthesis of a broad range of unsymmetrical dithioacetals consisting of one aromatic and one aliphatic thiol moiety from the corresponding aldehyde/thiol mixture. The
Lithium Bromide-Catalyzed Highly Chemoselective and Efficient Dithioacetalization of α,β-Unsaturated and Aromatic Aldehydes under Solvent-Free Conditions
作者:Habib Firouzabadi、Nasser Iranpoor、Babak Karimi
DOI:10.1055/s-1999-3679
日期:——
Chemoselective dithioacetalization of aromatic- and α,β-unsaturated aldehydes in the presence of other structurally different aldehydes and ketones was achieved efficiently in the presence of catalytic amounts of LiBr under solvent-free conditions. Due to the neutral reaction conditions, this method is compatible with acid sensitive substrates.
Lithium trifluoromethanesulfonate (LiOTf) as a highly efficient catalyst for chemoselective dithioacetalization of carbonyl compounds under neutral and solvent-free conditions
作者:Habib Firouzabadi、Babak Karimi、Shahram Eslami
DOI:10.1016/s0040-4039(99)00647-4
日期:1999.5
Various types of carbonylcompound can be efficiently and chemoselectively converted to their corresponding dithioacetals in the presence of catalytic amounts of lithium triflate under solvent-free conditions. Due to the neutrality of the reaction medium, this method is especially useful for acid sensitive substrates.