Two‐ and Three‐Component Reactions Leading to New Enamines Derived from 2,3‐Dicyanobut‐2‐enoates |
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| Authors: | Grzegorz Mlostoń Ma?gorzata Celeda Anthony Linden Heinz Heimgartner |
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| Institution: | 1. University of ?ód?, Department of Organic and Applied Chemistry, Narutowicza 68, PL‐90‐136 ?ód?, (phone: +48‐42‐6355761;2. fax: +48‐42‐6355380);3. Organisch‐Chemisches Institut der Universit?t Zürich, Winterthurerstrasse 190, CH‐8057 Zürich, (phone: +41‐44‐6354282;4. fax: +41‐44‐6356812) |
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| Abstract: | The three‐component reactions of 1‐azabicyclo1.1.0]butanes 1 , dicyanofumarates (E)‐ 5 , and MeOH or morpholine yielded azetidine enamines 8 and 9 with the cis‐orientation of the ester groups at the C?C bond ((E)‐configuration; Schemes 3 and 4). The structures of 8a and 9d were confirmed by X‐ray crystallography. The formation of the products is explained via the nucleophilic addition of 1 onto (E)‐ 5 , leading to a zwitterion of type 7 (Scheme 2), which is subsequently trapped by MeOH or morpholine ( 10a ), followed by elimination of HCN. Similarly, two‐component reactions between secondary amines 10a – 10c and (E)‐ 5 gave products 12 with an (E)‐enamine structure and (Z)‐oriented ester groups. On the other hand, two‐component reactions involving primary amines 10d – 10f or NH3 led to the formation of the corresponding (Z)‐enamines, in which the (E)‐orientation of ester groups was established. |
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| Keywords: | Multicomponent reactions 1‐Azabicyclo[1 1 0]butanes But‐2‐enoates 2 3‐dicyano‐ Morpholine Azetidine enamines Michael addition X‐Ray crystallography |
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