Regio- and stereoselective synthesis of polysubstituted 5-hydroxypyrrolidin-2-ones from 3-alkoxysuccinimides

The Wonderful World of β‐Enamino Diketones Chemistry

“…[ 56 ] The reaction is based upon the transformation of starting β‐enamino diketones 3 into their corresponding secondary β‐enamino diketones 31 , which, under DBU action (in CH 2 Cl 2 , at r. t., for 3 min), furnish the lactam 32 , which, in turn, undergoes 1,4‐addition of OH – , to finally furnish the 4‐acyl‐3,5‐dihydroxypyrrolone 33 – a great advance in the synthesis of 5‐hydroxypyrrolidin‐2‐ones (Scheme 13). [ 57 ] Compound 33 was treated with phenylhydrazine in CH 2 Cl 2 at r. t. for 40 min, which furnished pyrazole 34 at 87 % yield. The authors attempted to perform the reaction in a one‐pot procedure, initially forming 33 and then adding phenylhydrazine to allow cyclization.…”

Design, Synthesis, and Cholinesterase Inhibitory Activity of 4‐Substituted‐6‐(trihalomethyl)‐2‐methylsulfanyl Pyrimidines

“…Besides this, the introduction of a À CF 3 group into heterocycles can greatly influence both biological and chemical properties, due to the unique characteristics (e. g., lipophilicity, bioavailability, and metabolic stability) of the trifluoromethyl group. [9,10] β-Alkoxyvinyl trihalomethyl ketones have proven to be successful as CCC-building blocks in the regioselective synthesis of several heterocyclic scaffolds [11][12][13] (including pyrimidine rings), easily allowing the introduction of trihalomethyl groups. [14,15] On the other hand, allylic brominated β-alkoxyvinyl trihalomethyl ketones (enones) have been far less explored in heterocyclic synthesis, especially in regard to pyrimidines.…”

Brominated β-Alkoxyvinyl Trihalomethyl Ketones as Promising Synthons in Heterocyclic Synthesis

“…10 The C3 and the oxygen atom of the carbonyl group are nucleophilic sites; while the trihalomethyl group provides important molecular properties of the products and, in some circumstances (e.g., CCl 3 in basic conditions), it can be eliminated in order to generate further functionalization. [11][12][13][14][15][16][17][18][19] By inserting the CH 2 Br electrophilic center, the reactivity towards nucleophiles, especially nitrogen nucleophiles, is highly affected, which means that it can experience competition reactions, that is, 1,4-addition at C4 and allylic nucleophilic substitution at C5. Furthermore, this new electrophilic center can be used as an alkylating agent, which demonstrates the versatility of this crucial building block in the regioselective synthesis of several new, highly functionalized trichloromethyl-and trifluoromethyl-substituted heterocycles.…”