A new method for the synthesis of 2-cyclopenten-1-one-5- carboxylic ester derivatives via Rh2(OAc)4-mediated intramolecular C–H insertion reaction of 4Z-b-vinyl-a-diazo b-ketoesters
نویسندگان
چکیده
2-Cyclopenten-1-one-5-carboxylic ester derivatives 14 are synthesized in a four-step-reaction sequence starting from alkynyl aldehydes 9 via 4Z-b-vinyl-a-diazo b-ketoesters intermediate 8. The synthetic method for 8 is described. When the d substituent is an alkyl group, Rh(II)-mediated decomposition of the diazo compounds 8 led to an intramolecular C–H insertion to afford 2-cyclopenten-1-one-5carboxylic ester derivatives 14 in high yields. When the d substituent is an aryl group, 2-hydroxynaphthoate 15 is obtained exclusively. In both cases, no Wolff rearrangement product was observed. q 2005 Elsevier Ltd. All rights reserved.
منابع مشابه
Synthesis of oxygen-containing heterocyclic compounds based on the intramolecular O–H insertion and Wolff rearrangement of a-diazocarbonyl compounds
The addition products of Ti(IV)-enolate derived from b-keto a-diazo carbonyl compound to ketones or a,b-unsaturated compounds were subjected to Rh2(OAc)4-catalyzed and photo-induced diazo decomposition. The Rh2(OAc)4-catalyzed reaction afforded intramolecular O–H insertion products, while the photo-induced reaction gave Wolff rearrangement/intramolecular nucleophilic addition products. The tran...
متن کاملIntramolecular N–H insertion of -diazocarbonyls catalyzed by Cu(acac)2: An efficient route to derivatives of 3-oxoazetidines, 3-oxopyrrolidines and 3-oxopiperidines
Along with the intramolecular C–H insertion reactions by carbenoids, intramolecular N–H insertion reactions of α-diazocarbonyl substrates catalyzed by metal complex have received considerable attention in recent years. This type of insertion reaction has been shown to be a mild and efficient route to 4-, 5-, and 6-membered aza rings. A frequently cited example of this powerful approach is the M...
متن کاملA Facile One-Pot Synthesis of Functionalized N-Hydroxypyrrole Mediated by Vinyl-Triphenylphosphonium Salt
Protonation of the reactive intermediates generated in the raction between dalkyl acetylenedicarboxylates and triphenylphosphine by isonitrosoacetophenone leads to vinyltriphenylphosphonium salts, which undergo intramolecular Wittig reaction to produce dalkyl 4-phenyl-N-hydroxypyrrole-2,3-dicarboxylates in moderate yields.
متن کاملHighly diastereoselective synthesis of 3-hydroxy-2,2,3-trisubstituted indolines via intramolecular trapping of ammonium ylides with ketones.
A Rh2(OAc)4-catalyzed diazo decomposition reaction of diazo esters with 2-aminophenyl ketones is reported. A series of 3-hydroxy-2,2,3-trisubstituted indolines are produced in good yields with excellent diastereoselectivities via an intramolecular aldol-type trapping of ammonium ylides with ketone units.
متن کاملOne pot, Five-component Synthesis of Functionalized Piperidines Using Zn(OAc)2.2H2O as a Highly Efficient Catalyst
A convenient synthetic route for the synthesis of biologically active functionalized piperidines usingZn(OAc)2.2H2O as a highly efficient catalyst via five-component reaction of aromatic aldehydes,anilines and β-ketoesters at ambient temperature has studied. Mild reaction conditions, simplicity ofoperation and work-up procedures with no necessity of chromatographic purification steps, theavaila...
متن کامل