66373-96-4

Upstream product

• 54848-13-4 4',5'-dihydro-3'-phenylspiro 
• 616-45-5 2-pyrrolidinon 
• 100-42-5 styrene 
• 88-12-0 1-ethenyl-2-pyrrolidinone 
• 98-80-6 phenylboronic acid 
• 108-90-7 chlorobenzene 
• 93-97-0 benzoic acid anhydride 

Relevant academic research and scientific papers

Bipyridine-modulated palladium-catalyzed oxidative heck-type reactions of arylboronic acids with olefins

We have demonstrated that 4,4′-dimethyl 2,2′-bipyridine as ligand for Pd(II) catalysts was very efficient for oxidative Heck-type coupling reaction of arylboronic acids with olefins in DMA or CH3CN under atm air at 80 °C. The presence of chelated bipyridine ligand isindispensable to achieve high reaction yields and to suppress the formation of biphenyl as homocoupled byproduct.

Selective terminal heck arylation of vinyl ethers with aryl chlorides: A combined experimental-computational approach including synthesis of betaxolol

Reaction conditions have been developed for palladium-catalyzed terminal (β-) arylation of acyclic vinyl ethers with high regioselectivity using inexpensive aryl chlorides as starting materials and the P(t-Bu)3 releasing preligand [(t-Bu3)PH]BF4 as the key additive. This swift and straightforward protocol exploits non-inert conditions and controlled microwave heating to minimize handling and processing times and uses aqueous DMF or environmentally friendly PEG-200 as the reaction medium. The selectivity for linear β-product in PEG-200 is slightly higher than in aqueous DMF. DFT calculations support a ligand-driven selectivity rationale, where the electronic and steric influence of bulky P(t-Bu)3 ligand provides improved β-selectivity in the essential insertion step also with electron-rich aryl chlorides. A tentative computational rationalization of the improved selectivity in non-methylated PEG is discussed. Finally the synthetic methodology was used to provide efficient access to linear p-[2- (cyclopropylmethoxy)-ethyl] phenol from p-nitrophenyl chloride, a key intermediate in the synthesis of the β-adrenergic blocking agent Betaxolol.

Dioxygen-promoted regioselective oxidative Heck arylations of electron-rich olefins with arylboronic acids

Arylations of electron-rich heteroatom-substituted olefins were performed with arylboronic acids. This appears to constitute the first example of palladium(II)-catalyzed internal Heck arylations. The novel protocol exploits oxygen gas for environmentally benign reoxidation and a stable 1,10-phenanthroline bidentate ligand to promote the palladium(II) regeneration and to control the regioselectivity. Internal arylation is strongly favored with electron-rich arylboronic acids. DFT calculations support a charge-driven selectivity rationale, where phenyls substituted with electron-donating groups prefer the electron-poor α-carbon of the olefin. Experiments, verified by calculations, confirm the cationic nature of the catalytic route. This Heck methodology provides a facile and mild access to functionalized enamides. Controlled microwave heating and increased oxygen pressure were used to further reduce the reaction time to 1 h.

Dioxygen-Coupled Oxidative Amination of Styrene

Dioxygen-coupled oxidative amination of olefins is an attractive, but challenging, catalytic transformation. The present work describes the first general method for intermolecular oxidative amination of aryl olefins with molecular oxygen as the stoichiometric oxidant. This palladium-catalyzed reactivity is compatible with several different nitrogen nucleophiles, including oxazolidinone, phthalimide, pyrrolidinone, and p-toluenesulfonamide. The presence of a catalytic quantity of a Bronsted base in the reaction increases the catalytic activity and switches the reaction regioselectivity. Copyright

Heck reactions without salt formation: Aromatic carboxylic anhydrides as arylating agents

Environmentally benign and economical production of arylated olefins can be achieved by a new variant of the Heck reaction in which no halogen salts are formed. The trick is the use of aromatic carboxylic anhydrides 1 as arylating agents. With halide-activated palladium chloride as catalyst, which requires no phosphane ligands, the olefins 2 can be prepared according to Equation (a) in good yields.

Rearrangement of isoxazoline-5-spiro derivatives. Part 7. Thermal rearrangement of 4,5-dihydro and tetrahydroisoxazole-5-spirocyclobutanes to azepin-4-one derivatives

Some representative 4,5-dihydro and tetrahydroisoxazole-5-spirocyclobutanes have been synthesized by 1,3-dipolar cycloaddition of alkylidenecyclobutanes to nitrile oxides and nitrones, respectively. When subjected to flash vacuum thermolysis conditions, the spiranic cycloadducts rearranged to afford mainly the desired azepin-4-one derivatives. In addition, the isoxazoline cycloadducts gave unexpected by-products, which were identified as 1-alkenyl-2-pyrrolidinones. Analogies and differences with respect to the lower homologue cyclopropanes are evidenced in both cycloaddition and rearrangement reactions.