Synlett 2022; 33(11): 1052-1058
DOI: 10.1055/a-1817-0882
letter

DBU- and DABCO-Promoted Selective Access to 2,5-Diarylnitrobenzoates and Cyclohexenones via One-Pot Reactions

Shikha Singh Rathor
,
Debashis Majee
,
The authors thank SERB-DST research grant (CRG/2018/001111), Government of India for generous financial support and SIC facility, Indian Institute of Technology (IIT) Indore.


Abstract

Remarkable organobase-controlled selective synthesis of a wide breadth of valuable 2,5-diaryl-4-nitrobenzoates and 1-hydroxy-4-oxocyclohexencarboxylates bearing a tetrasubstituted stereogenic carbon is reported. This one-pot cyclization reaction operates between a bunch of 3-nitroallylarenes and β,γ-unsaturated α-ketocarbonyls by carefully choosing DBU or DABCO as an organobase under aerobic conditions. Notably, as a nucleophilic base, DABCO favors the Nef reaction over the dehydration–aerial oxidation process, aiming for unexpected cyclohexanone architectures. Moreover, this operationally simple technique holds a few positive qualities: good yields with diastereoselectivities (dr ≤ 91:9), broad substrate scope, no added oxidant, excellent functional group compatibility, 100% carbon-economical, etc. Furthermore, the obtained 4-nitrobenzoate framework has been utilized for the synthesis of a range of valuable compounds such as 2-phenylcarbazole-3-carboxylate, 3-bromoaniline derivative, and 2,5-diphenylbenzoic acid, among others.

Supporting Information



Publication History

Received: 01 February 2022

Accepted after revision: 05 April 2022

Accepted Manuscript online:
05 April 2022

Article published online:
09 May 2022

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