An Improved Protocol for Palladium‐Catalyzed Alkoxycarbonylations of Aryl Chlorides with Alkyl Formates

Abstract

The palladium-catalyzed alkoxycarbonylation of aryl and heteroaryl halides using butyl formate has been investigated. In the presence of palladium(II) acetate/n-butylbis(1-adamantyl)phosphine (L1), and 1,8-diazabicycloA C H T U N G T R E N N U N G [5.4.0]undec-7-ene (DBU) as base for the first time non-activated chloroarenes can be conveniently carbonylated in good yields.

Palladium‐Catalyzed Carbonylations of Aryl Bromides using Paraformaldehyde: Synthesis of Aldehydes and Esters

“…Inspired by the above‐mentioned reports and also based on our continuous interest in carbonylation reactions,13 we recently started to explore carbonylation reactions with alternative CO sources 9c. 13 Herein, we report the first successful application of readily available paraformaldehyde in a CO‐gas‐free synthetic protocol for the palladium‐catalyzed carbonylations of aryl halides (Scheme ).…”

Synthesis of 4H‐Benzo[e][1,3]oxazin‐4‐ones by a Carbonylation–Cyclization Domino Reaction of ortho‐Halophenols and Cyanamide

“…[7][8][9][10][11][12] Palladium-catalyzed carbonylation reactions such as aminocarbonylation and cross-coupling reactions have become essentialt ools for synthesizingh eterocycles and immense effort has been invested in developing safer methods for handling the toxic carbon monoxide gas. [13][14][15] Over the last decade, several non-gaseous CO sourcesh ave been reported both for in situ and ex situ use, for example, formates, [16,17] formamides, [18] aldehydes, [19] formic acid [20] and metal carbonyls such as Mo(CO) 6 . [21][22][23] In addition, Pd-catalyzed decomposition of 9-methylfluorene-9-carbonyl chloride (COgen) [24] and fluoride-mediated CO release from silacarboxylic acid [25] enable the use of substoichiometric amountso fC O as wella st he possibility to isotopicallyl abel the carbonyl carbon.F urthermore, base-mediated decomposition of oxalyl chloride [26] and chloroform [27,28] have been reported as effective CO-generating strategies for carbonylation chemistry.…”

Heterogeneous Phase Microwave-Assisted Reactions under CO2 or CO Pressure

“…A number of protocols that see CO released in situ have been developed to circumvent the safety issues surrounding this invisible, odourless, tasteless and highly toxic gas [13,14,15,16,17,18,19]. These methods include the use of CO-equivalents (alkyl formates [20], formic acid, formic anhydride, formamide [21,22,23], N -substituted formamide [24], carbamoylstannanes [25], carbamoylsilane [26]), and CO-releasing reagents (metal carbonyls [27]). Unfortunately, these reagents are relatively expensive and sometimes require harsh reaction conditions for CO release (strong base combined with high temperatures and long reaction times).…”