Conjugated ynone

The reaction between DAP and conjugated ynones is reported to give two products (17 and 18), one being a tautomer of the anticipated second product (Scheme 7).49... 

In much the same way that palladium complexes can activate alkynes towards intramolecular cyclization upon Jt-complexation, a similar reaction manifold has also been employed using allenes. This chemistry has been commonly employed in the assembly of substituted furans. For example, Huang reported that conjugated ynones can undergo isomerization under palladium-catalyzed conditions to form furans (Scheme 6.23) [31], This reaction was postulated to proceed via a palladium-... 

X. Conjugated ynones Binal-H NB-Enantrane LiAlH -MEP-ArOH B-Ipc-9-BBN, THF... 

A new synthesis of pyrroles from l-amino-3-alkyn-2-ols has been reported involving Pd" as a catalyst. The yields are fairly good and the starting materials are easily accessible from conjugated ynones (Scheme 32). ... 

Conjugated ynones are easily accessible via palladium-catalysed condensation of terminal alkynes with acid chlorides and this was used to generate several 1,5-bis... 

Scheme 56 A regioselective reaction between a conjugated ynone and methyl thioglycolate giving a thiophene-2-ester [86]...

Scheme 59 Palladium-catalysed synthesis of a conjugated ynone and its reaction with methyl thioglycolate giving diethyl [2,2 4, 2" 5",4" 2", 2""-quinquethiophene]-5, 5" -dicarboxylate [89]...

Recently, the Tu group reported the coupling of amino-functionalized malonates 202, benzaldehydes 203, and conjugated ynones 204 to furnish 2,5-dihydropyrroles 205 (Scheme 42.47) [103]. 

Scheme 42.47 Synthesis of dihydropyrroles by 1,3-dipolar cycloaddition using conjugated ynones catalyzed by phosphoric acid catalyst 101a.

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