- METHOD FOR THE DECARBOXYLATIVE HYDROFORMYLATION OF ALPHA, BETA- UNSATURATED CARBOXYLIC ACIDS
-
The present invention relates to a process for preparing aldehydes by reacting an α,β-unsaturated carboxylic acid or a salt thereof with carbon monoxide and hydrogen in the presence of a catalyst comprising at least one complex of a metal of transition group VIII of the Periodic Table of the Elements with at least one compound of the formula (I), where Pn is pnicogen; W is a divalent bridging group having from 1 to 8 bridge atoms between the flanking bonds; R1 is a functional group capable of forming at least one intermolecular, noncovalent bond with the —X(═O)OH group of the compound of the formula (I); R2, R3 are each in each case optionally substituted alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl or together with the pnicogen atom and together with the groups Y2 and Y3 if present form an optionally fused and optionally substituted 5- to 8-membered heterocycle; a, b and c are each 0 or 1; and Y1,2,3 are each, independently of one another, O, S, NRa or SiRbRc, where Ra,b,c are each H or in each case optionally substituted alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl; and the use of the above-described catalyst for the decarboxylative hydroformylation of α,β-unsaturated carboxylic acids.
- -
-
Page/Page column 11
(2011/02/25)
-
- A supramolecular catalyst for the decarboxylative hydroformylation of α,β-unsaturated carboxylic acids
-
(Chemical Equation Presented) Head 'em up, move 'em out, aldehyde! A catalytic transformation of α,β-unsaturated carboxylic acids into aldehydes through a hydroformylation-decarboxylation process has been developed (see scheme; Do = donor ligand, FG1 and FG2 = complementary functional groups). The reaction proceeds at mild conditions, tolerates many functional groups, and liberates CO2 as the only stoichiometric by-product.
- Smejkal, Tomas,Breit, Bernhard
-
p. 3946 - 3949
(2008/12/23)
-
- A New Synthesis of 8-(ω-Carbomethoxyhexyl)-11-hydroxycyclopent-8(12)-ene-9-one, a Versatile Prostaglandin Intermediate
-
8-(ω-Carbomethoxyhexyl)-11-hydroxycyclopent-8(12)-ene-9-one (V), a versatile prostaglandin synthon, has been synthesised starting from easily accesible undecylenic acid (VI).The synthesis involves preparation of dihydroxy undecanoic acid (IX) and its methyl ester (X), methyl 9-formylnonanoate (XI), the monoester (XII) and the corresponding unsaturated acid (XIII), γ-lactone (XIV), cyclopentenone acid (XV) and finally the all important PG-intermediate 2-(ω-carbomethoxyhexyl)cyclopentenone (IV).Its reduction with sodium borohydride gives the saturated alcohol (XVI), which via oxidation with Jones' reagent and bromination-dehydrobromination sequence could be converted back to IV.However, IV, on reduction with aluminium isopropoxide gives the allylic alcohol (XXIII), which is converted via acetylation into the acetate (XXIV).Subsequent oxidation of acetate (XXIV) with t-butyl chromate yields the keto-acetate (XXV), which on reduction with aluminium isopropoxide furnishes the hydroxy acetates (XXXII).The hydroxyl group in XXXII is protected as tetrahydropyranyloxy derivative (XXXIII).Hydrolysis of XXXIII with alkali leads to the hydroxy acids (XXXIV).Oxidation of XXXIV with Jones' reagent at low temperature for a short period yields the keto-acid (XXXV), which is esterified to give the ester (XXXVI).Finally, removal of the pyranyloxy group from XXXVI furnishes the versatile synthon (V), identical with the sample prepared by a known procedure.
- Thakur, S. B.,Jadhav, K. S.,Bhattacharyya, S. C.
-
p. 675 - 683
(2007/10/02)
-
