Carbonylation, palladium-catalyzed

Aryl Halide Carbonylations. Palladium-catalyzed carbony-lation of aryl halides is an efficient way to produce carboxylic acid derivatives. Aminocarbonylation of aryl chlorides has heen performed using Mo(CO)6 as the carbon monoxide source and a catalyst derived from TTBHBF4 andpalladacycle 1 under microwave irradiation (170 °C). Tbe catalyst system was also applied to the carbonylation of 4-chloro-l-trifluoromethylbenzene in hutanol to... 

Vinyl iodides/triflates have been reported to undergo carbonylative palladium-catalyzed coupling reaction with organostannanes, organoboron derivatives, and metal acetylide. The palladium-catalyzed three-component coupling reaction of vinyl iodides with trimethyl- or tributylvinylstannanes gives unsymmetrical divinyl... 

The carbonylative palladium-catalyzed reactions discussed in this section proceed by oxidative addition of palladium (0) to the carbon-X bond of aryl/vinyl/acyl halides and pseudohalides followed by carbon monoxide insertion, giving rise to an acylpalla-dium intermediate. The acylpalladium intermediate can in turn react with various tethered nucleophiles (a), be involved in activation/hetero or carbopalladation steps with unsaturated carbon-carbon bonds (b), or participate in cascade reactions (c) (Scheme 13.1). 

Oxidative Carbonylation of Ethylene—Elimination of Alcohol from p-Alkoxypropionates. Spectacular progress in the 1970s led to the rapid development of organotransition-metal chemistry, particularly to catalyze olefin reactions (93,94). A number of patents have been issued (28,95—97) for the oxidative carbonylation of ethylene to provide acryUc acid and esters. The procedure is based on the palladium catalyzed carbonylation of ethylene in the Hquid phase at temperatures of 50—200°C. Esters are formed when alcohols are included. Anhydrous conditions are desirable to minimize the formation of by-products including acetaldehyde and carbon dioxide (see Acetaldehyde). 

Dihydrouracils (27) can be obtained in one step by a palladium-catalyzed carbonylation of (28). The key intermediate is believed to be 2-trifluoro-methylpropenoyl palladium (82TL4099). 

Scheme 8.15. Synthesis of Ketones, Esters, Carboxylic Acids, and Amides by Palladium-Catalyzed Carbonylation and Acylation... 

Thus far, we have discovered and demonstrated a new and effident method for the synthesis of indoles from various carbonyl compounds. This, in conjunction with the use of alkyries in the palladium-catalyzed indolization, widens the spectrum of indoles that can be prepared by these means. The simple procedure, mild reaction conditions, and ready availability of the starting materials render these methods valuable additions to indole chemistry. We next extended this method to the synthesis of the indole core of a PGD2 receptor antagonist, laropiprant 3. 

Later, a nickel-catalyzed cascade conversion of propargyl halides and propargyl alcohol into a pyrone in water was reported. The reaction involved a carbonylation by CO and a cyanation by KCN (Eq. 4.55).96 Recently, Gabriele et al. explored a facile synthesis of maleic acids by palladium catalyzed-oxidative carbonylation of terminal alkynes in aqueous DME (1,2-dimethoxyethane) (Eq. 4.56).97... 

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