temperature readily affords cyclic enol carbonates with either five- or six-membered rings. Reaction with potassium tert-butoxide results in the in situ formation of an enolate which after transmetallation participates in aldol or Mannich reactions. Alternatively, the potassium enolates can be trapped with silylating or triflating agents. The regio- and stereoselective generation of silyl enol ethers with up
[EN] PROCESS FOR PREPARING CYCLIC CARBONATES<br/>[FR] PROCÉDÉ DE PRÉPARATION DE CARBONATES CYCLIQUES
申请人:BASF SE
公开号:WO2019034648A1
公开(公告)日:2019-02-21
The present invention relates to a process for preparing cyclic carbonates of formula Ia or Ib or mixtures thereof (Ia) (Ib) comprising the process step: a) reacting a propargylic alcohol of formula II (II) with carbon dioxide in the presence of at least one transition metal catalyst TMC1, which comprises a transition metal selected from metals of groups 10, 11 and 12 of the periodic table of the elements according to IUPAC and at least one bulky ligand.
Process for manufacturing cyclocarbonates using a silver salt catalyst
申请人:Roche Vitamins Inc.
公开号:US05817838A1
公开(公告)日:1998-10-06
A process for the manufacture of 4,4-disubstituted 5-methylene-1,3-dioxolan-2-ones ("cyclocarbonates") of the formula: ##STR1## wherein R.sup.1 and R.sup.2 each independently signify a saturated or olefinically-unsaturated aliphatic group or an aromatic group, or R.sup.1 and R.sup.2 together form tetra- or pentamethylene, by reacting a corresponding 3,3-disubstituted prop-1-yn-3-ol of the formula HC.tbd.C--C(R.sup.1)(R.sup.2)--OH (II) with carbon dioxide in the presence of a quaternary ammonium or phosphonium salt as the catalyst comprises using a silver salt as a further catalyst. An alkali metal or quaternary ammonium or phosphonium salt of a carboxylic acid can also be used to increase the catalytic performance of the silver salt catalyst. Moreover, the addition of triphenylphosphine serves to accelerate the reaction to some extent. The silver salts catalyze this process significantly better than the previously utilized copper salts. Advantageously, the process uses much smaller amounts of catalyst, significantly shortens reaction times, and mandates less drastic reaction conditions. Cyclocarbonates produced by this process are valuable intermediates for the production of polymerizates and other useful substances, such as dyestuffs and carotenoids.
A Rh(III)-catalyzed C–H bond activation and subsequent [4+1] annulation of benzamides with vinyl cyclic carbonates have been developed for the synthesis of isoindolinones, in which the electron-rich alkenes could serve as one-carbon units. This reaction proceeds smoothly with high regioselectivity under oxidant- and silver-free conditions and exhibits broad substrate scope and functional group tolerance
Verfahren zur Herstellung von 4,4-disubstituierten 5-Methylen-1,3-dioxolan-2-onen
申请人:BASF Aktiengesellschaft
公开号:EP0175241A1
公开(公告)日:1986-03-26
Herstellung von 4,4-disubstituierten 5-Methylen-1,3-dioxolan-2-onen I
(R1 = org. Rest; R2 = C1-C4-Alkyl; R1 + R2 = 5- oder 6-Ring) durch Umsetzung von Prop-1-in-3-olen R1R2C(OH)-C≡CH (II) mit C02, einem Kupfersalz und einer tertiären Base, indem man hierbei ein quartäres Ammonium- oder Phosphoniumsalz mitverwendet.