16078-39-0

Upstream product

• 330467-78-2 1-(2-bromobenzoyl)-1,2,3,4-tetrahydroquinoline 
• 292638-85-8 acrylic acid methyl ester 
• 333349-63-6 1-(2-iodobenzoyl)-1,2,3,4-tetrahydroquinoline 
• 67-56-1 methanol 
• 24319-84-4 (2-aminophenyl)(3,4-dihydroquinolin-1(2H)-yl)methanone 

Relevant academic research and scientific papers

Development of radical addition-cyclization-elimination reaction of oxime ether and its application to formal synthesis of (±)-martinelline

Radical addition-cyclization-elimination (RACE) reaction of oxime ether carrying unsaturated ester provides a novel method for the construction of pyrroloquinoline. Treatment of oxime ethers with Bu3SnH and AIBN gave N-norpyrroloquinoline as a major product, which was also obtained by the radical reaction of the corresponding hydrazone and imine. The radical reaction of aldehyde and ketone carrying unsaturated ester proceeded stereoselectively to give cis-furoquinolines and cis-hydroxyesters. The RACE reactions by using each of Bu3SnNMe2, Bu3SnD, and/or D2O were also examined in order to propose a reaction pathway to N-norpyrroloquinoline. Furthermore, the synthetic utility of RACE reaction is demonstrated by preparation of a key intermediate for the synthesis of (±)-martinelline.

Exploratory synthetic studies of the α-methoxylation of amides via cuprous ion-promoted decomposition of o-diazobenzamides

A convenient nonelectrochemical amide oxidation method has been developed. The process involves a cuprous ion-promoted decomposition of o-diazobenzamides like 4, generated in situ from the corresponding o-aminobenzamides, to give N-acyliminium ion intermediate 9 via a 1,5-H-atom transfer, followed by metal-catalyzed oxidation of the resulting α-amidyl radical. The transformation produces α-methoxybenzamides 15 in good yields. An attempt was made to apply this oxidation method to a total synthesis of the alkaloid (-)-anisomycin (16). Scalemic o-aminobenzamide pyrrolidine derivatives 18a/18b underwent oxidation to give α-methoxylated amide substrates 19a/19b, respectively, in good yields. However, alkylation of the N-acyliminium intermediate 20 with (p-methoxybenzyl)magnesium chloride gave the undesired anti-compounds 22a/22b as the major products. The amide oxidation exhibits good regioselectivity with many unsymmetrical 2-substituted piperidine and pyrrolidine systems. In general, it appears that the larger the C-2 substituent, the greater the methylene/methine H-atom abstraction ratio. A mechanistic rationale for this selectivity is suggested based upon amide rotamer populations. An extension of this methodology can be used to conduct two sequential amide oxidations using readily prepared 2-amino-6-nitrobenzamides such as 68 and 69.