Microwave-Assisted N-Allylation/Homoallylation-RCM Approach: Access to Pyrrole-, Pyridine-, or Azepine-Appended...

A facile and diversity-oriented approach has been developed for the synthesis of pyrrole-, pyridine-, or azepine-appended (het)aryl aminoamides via the N-allylation/homoallylation-ring-closing metathesis (RCM) strategy. Microwave condition was efficiently utilized for N-allylation of (het)aryl aminoamides to synthesize di-, tri-, and tetra-allyl/homoallylated RCM substrates in good yields. All of the RCM substrates were successfully converted to respective pyrroles 6a-h, 13a,b, 15a,b, pyridines 11a-d, 13c, and azepines 7a,b via RCM. All of the five-, six-, and seven-membered N-heterocycles were synthesized in shorter reaction times with excellent yields without isomerization products. A one-pot reaction to synthesize compounds 6a and 6b without isolating corresponding RCM substrates was achieved successfully. The synthetic utility of the compound 6b has been demonstrated by synthesizing biaryl derivatives 17a,b under the microwave Suzuki coupling reaction condition.