2-Azapentadienyl anion regioselectivity

Derivatives of azabutadiene react with Gly-OEt to give pyrrole-2-carbox-ylates. This reaction, which is assumed to occur via an azapentadienyl anion, allows the synthesis of 3,5-diarylpyrrole-2-carboxylates in a regioselective manner (Scheme 10) (82JOC1696). 

Azapentadienyl anion (31), readily prepared by deprotonation of the /V-allylimine, reacts with carbonyl compounds at either the a- or the 7-position (equation 10). The regioselectivity depends upon the reaction conditions. 1-Azapentadienyl anion (32 equation 11), prepared from the cyclohexylimine of ti-glaldehyde and LDA, reacts with aldehydes and ketones to give the 7-capture products in the presence of HMPA or the a-capture products in the absence of HMPA. ... 

---

See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ ]

---