Palladium-Catalyzed Molybdenum Hexacarbonyl-Mediated Gas-Free Carbonylative Reactions

Abstract

This account summarizes Pd(0)-catalyzed Mo(CO)6-mediated gas-free carbonylative reactions published in the period October 2011 to May 2018. Presented reactions include inter- and intramolecular carbonylations, carbonylative cross-couplings, and carbonylative multicomponent reactions using Mo(CO)6 as a solid source of CO. The presented methodologies were developed mainly for small-scale applications, avoiding the problematic use of gaseous CO in a standard laboratory. In most cases, the reported Mo(CO)6-mediated carbonylations were conducted in sealed vials or by using two-chamber solutions.1 Introduction2 Recent Developments2.1 New CO Sources2.2 Two-Chamber System for ex Situ CO Generation2.3 Multicomponent Carbonylations3 Carbonylations with N and O Nucleophiles4 Carbonylative Cross-Coupling Reactions with Organometallics5 Carbonylative Cascade Reactions6 Carbonylative Cascade, Multistep Reactions7 Summary and Outlook

Palladium‐Catalyzed One‐Pot Coupling / Cyclization through Mo(CO)6 as the Carbon Monoxide Donor: Synthesis of Quinazolinones

“…Based on the above experimental results and the results of the previous literatures, [23][24][25][26][27][28] a plausible reaction mechanism is inferred in Scheme 2. Above all, transmetalation of bromobenzene with PdCl 2 and BuPAd 2 bring about the Palladium-Complex A.…”

“…In view of the advantages above, Mo(CO) 6 has been widely used as a carbon monoxide replacement in amino-carbonations, [21] alkoxycarbonylations, [22] carbonyl cross-couplings [23] and synthesis of carbonyl-containing heterocycles. [24] In this article, we report a new method for the synthesis of quinazolinones using Mo(CO) 6 as a carbon monoxide donor which services as carbon unit to build new CÀ N and CÀ C bonds (Scheme 1, 1 h).…”

Gas‐Free Amino‐ and Alkoxycarbonylation of Aryl Iodides in a Bioinspired Deep Eutectic Solvent with Mo(CO)6 as a Safe CO Source

“…This has led to a safer and more accessible implementation of these reactions in a variety of experimental protocols: formic acid, [12] alkyl‐ and arylformates, [13] N ‐formylsaccharin, [14] chloroform, [15] acyl chlorides, [16] carbon dioxide, [17] silanecarboxylic acid [18] and metal carbonyls [19–21] have been successfully employed as synthetic equivalents of gaseous CO. Among metal carbonyls, the potential of molybdenum hexacarbonyl to facilitate carbonylation reactions has recently attracted significant consideration due to its ability to provide a safe, practical, and a manageable solid source of carbon monoxide [22] . Mo(CO) 6 can release CO either through thermic treatment, [23] or ligand exchange with several Lewis bases such as DBU, [24] piperidine, [25] or MeCN [26] …”

“…In an effort to identify environmentally friendly and safe replacements for conventional Pd‐catalyzed carbonylation procedures relying on gaseous CO, a remarkable research study has been conducted that exploits the utility of Mo(CO) 6 as carbon monoxide source [22] …”

Nickel-catalysed carbonylative homologation of aryl iodides

“…Additionally, Ni(CO) 4 has limited reactivity in oxidative addition with substrates, due to the full coordination of CO on the metal center. Based on our previous experience in developing new CO-gas-free carbonylation reactions [21][22][23][24][25][26][27] , we assume the usage of Mo(CO) 6 as a solid CO source could be an ideal option for exploring nickel catalyst in carbonylation chemistry 28,29 .…”