Diastereoselective Dimerisation of Alkenylthiazolines: A Combined Synthetic and Computational Study

Abstract

The acylative dimerisation of 2‐alkenyl‐1,3‐thiazolines 1 gives compounds 3 and 8 upon treatment with trichloroacetyl chloride and trifluoroacetic anhydride, respectively. This reaction is completely diastereoselective, in particular giving only a single double‐bond isomer. The scope of the reaction has been evaluated synthetically, while a computational study has elucidated the mechanism of the reaction and the origin of stereocontrol. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

New Efficient Eco‐Friendly Supported Catalysts for the Synthesis of Amides with Antioxidant and Anti‐Inflammatory Properties

“…The reported strategies for the synthesis of idrocilamide ( 1 ) are depicted in Scheme . Eight different procedures were described . The most documented is the treatment of cinnamic acid with ethanolamine in different conditions: 1‐i) methylchloroformate, triethylamine in CH 2 Cl 2 at room temperature to provide idrocilamide 1 in 82 % yield; 1‐ii) similar conditions have been also reported by Xiu, J.‐H.…”

“…Reported synthetic procedures to access idrocilamide 1. [12][13][14][15][16][17][18][19][20][21] Reagents and conditions: i) CH 2 base and constitute the best transformation described in the literature to obtain idrocilamide (1) in terms of final yield (87 %). [21] Ultimately, from all these considerations, the major part of these methods led to modest conversions, were often realized in dichloromethane generating chlorinated effluents and used superficial reagents, which is problematic for industrial production.…”

“…started from cinnamic acid which, upon activation in presence of thionyl chloride to provide cinnamoyl chloride, was treated with ethanolamine to obtain final idrocilamide ( 1 ) without specifying the final yield. Two contributions describe the synthesis of compound 1 by direct treatment of cinnamoyl chloride with ethanolamine in CH 2 Cl 2 followed by alkaline treatment by using aqueous sodium carbonate (4‐vii) or triethylamine (4‐viii) to furnish the target amide in good yield. Another synthetic pathway (2) started from an α,β‐unsaturated ester that underwent methanolysis in the presence of trimethylphosphine at room temperature and provided 49 % of idrocilamide ( 1 ) .…”

“…[12][13][14][15][16][17][18][19][20][21] The most documented is the treatment of cinnamic acid with ethanolamine in different conditions: 1-i) methylchloroformate, triethylamine in CH 2 Cl 2 at room temperature to provide idrocilamide 1 in 82 % yield; [12] 1-ii) similar conditions have been also reported by Xiu, J.-H. and coworkers [13] and allowed to obtain the target idrocilamide in 75 % yield; 1-iii) the reaction between cinnamic acid and ethanolamine conducted in presence of sulfuric acid furnished 68 % of idrocilamide; [14] 1-iv) the two-step procedure described by Zhang, J.-S. [15] started from cinnamic acid which, upon activation in presence of thionyl chloride to provide cinnamoyl chloride, was treated with ethanolamine to obtain final idrocilamide (1) without specifying the final yield. Two contributions describe the synthesis of compound 1 by direct treatment of cinnamoyl chloride with ethanolamine in CH 2 Cl 2 followed by alkaline treatment by using aqueous sodium carbonate (4-vii) [16] or triethylamine (4-viii) [17] to furnish the target amide in good yield. Another synthetic pathway (2) started from an α,β-unsaturated ester that underwent methanolysis in the presence of trimethylphosphine at room temperature and provided 49 % of idrocilamide (1).…”

“… Reported synthetic procedures to access idrocilamide 1 . Reagents and conditions: i) CH 2 Cl 2 , Et 3 N, ClCO 2 Me, r.t, 2 h (82 %); ii) Et 3 N, ClCO 2 Me, CH 2 Cl 2 , cooled to r.t, 1 h, then CH 2 Cl 2 , cooled, 2 h, r.t then aq.…”