Desymmetrization of Cyclopentene‐1,3‐Diones via Alkylation, Arylation, Amidation and Cycloaddition Reactions

Abstract

Desymmetrization of prochiral cyclopentene‐1,3‐diones for the synthesis of various natural products and moieties of pharmaceutically active compounds, is a very challenging and competitive area of research in organic synthesis now a days. It is a very powerful strategy to provide quaternary stereocenter having different functionality, which is very difficult to install by other C−C bond‐forming methods. This review describes an elaborative discussion of desymmetrization of cyclopentene‐1,3‐diones (racemic and asymmetric) via different alkylation, arylation, amidation and cycloaddition process for the last decades.

Unveiling new frontiers: Bast fiber‐reinforced polymer composites and their mechanical properties

“…Reacting with the hydroxyl groups and then modifying the different chemical functional groups are two of the essential mechanisms to improve the chemical bonding of the composite materials. 1,[99][100][101] The important chemical treatments are alkalization, 102 etherification, 103,104 quaternization, 105 isocyanation, 106,107 amidation, 108,109 acylation, 110 cyanoethylation, 111 and silanization. 112 Komal et al 113 evaluated different behavior of banana fiber when they were treated through an alkaline medium.…”

Catalytic asymmetric indolization by a desymmetrizing [3 + 2] annulation strategy

“…When a prochiral carbonyl substrate was employed, the asymmetric [3 + 2] indolization shall be feasible. In light of our experience in asymmetric synthesis by rhodium-catalyzed conjugate addition of arylborons to α,β-unsaturated carbonyls, 13 we proposed to use ortho -amino arylborons under rhodium catalysis to construct the C–C bond, 14,15 and 2,2-disubstituted cyclopentene-1,3-diones 16 were selected as the prochiral carbonyl substrates. Ideally, the reactions between ortho -aminoarylborons and 2,2-disubstituted cyclopentene-1,3-diones could proceed via a conjugate addition/5- exo -trig cyclization/dehydration cascade to produce cyclopenta[ b ]indoles bearing an all-carbon quaternary stereocenter (Scheme 1c-middle).…”

Benzo[4,5]imidazo[1,2-a]pyridines and benzo[4,5]imidazo[1,2-a]pyrimidines: recent advancements in synthesis of two diversely important heterocyclic motifs and their derivatives

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