Iodoenolcyclization of 2-Allyl Substituted b-Keto Esters under Thermodynamic Conditions
摘要:
An improved procedure for the synthesis of diastereo-enriched tetrasubstituted 4,5-dihydrofurans by using I-2-induced enolcyclization of beta-keto esters is reported. The reactions using I-2 in anhydrous MeCN are considered under thermodynamic control and the more stable trans isomers are preferentially produced.
A new route to 2-alkenyl-1,3-dicarbonyl compounds, intermediates in the synthesis of dihydrofurans
摘要:
A two step synthetic strategy for obtaining 2-alkenyl-1,3-dicarbonyl compounds from the corresponding 1,3-dicarbonyl compounds is reported. The method is based on a Knoevenagel condensation and a Michael addition using a high order organocuprate procedure, and proves to be of general value, Obtained compounds are useful starting materials for the synthesis of furan derivatives, (C) 2002 Elsevier Science Ltd. All rights reserved.
Regioselective Rhodium-Catalyzed Addition of β-Keto Esters, β-Keto Amides, and 1,3-Diketones to Internal Alkynes
作者:Thorsten M. Beck、Bernhard Breit
DOI:10.1002/ejoc.201601230
日期:2016.12
The first rhodium-catalyzed regioselective addition of 1,3-dicarbonyl compounds, including β-keto esters, β-keto amides, and 1,3-diketones, to internal alkynes furnishes branched allylic compounds. By applying RhI/DPEphos/TFA as the catalytic system, aliphatic as well as aromatic internal methyl-substituted alkynes act as suitable substrates to yield valuable branched α-allylated 1,3-dicarbonyl compounds