During the last two decades, tetrabutylammonium bromide (TBAB) has gained significant attention as an efficient metal-free homogeneous phase-transfer catalyst. A catalytic amount of TBAB is sufficient to catalyze various alkylation, oxidation, reduction, and esterification processes. It is also employed as an efficient co-catalyst for numerous coupling reactions. It has also acted as an efficient zwitterionic solvent in many organic transformations under molten conditions. In this review, we have summarized the recent developments on TBAB-catalyzed protocols for the efficient synthesis of various biologically promising heterocyclic scaffolds.

Tetrabutylammonium Bromide (TBAB) Catalyzed Synthesis of Bioactive Heterocycles.

Recent Advances in the Synthesis of Imidazolines (2009–2020)

Water mediated TBAB catalyzed synthesis of spiro-indoline-pyrano[3,2-c]quinolines as a-Amylase Inhibitor and In Silico Studies

Visible Light Organo‐Photocatalytic Synthesis of 3‐Imidazolines

Green and rapid and instrumental one-pot method for the synthesis of imidazolines having potential anti-SARS-CoV-2 main protease activity

Green Synthesis of 2‐Substituted Imidazolines using Hydrogen Peroxide Catalyzed by Tungstophosphoric Acid and Tetrabutylammonium Bromide in Water

The invention discloses an anti-trypanosome anticancer natural product Cryptofolione synthesizing method. The synthesizing method disclosed by the invention comprises the steps: after acrolein and silyl enol ether are utilized to perform Mukaiyama aldol reaction, sodium borohydride is used for reducing ketone into alcohol, and then pyridinium p-toluenesulfonate refluxes in a methylbenzene solutionto obtain compound shown in a formula 5; after cinnamyl aldehyde and an evans chiral aid are used for performing evans aldol reaction, diisobutyl aluminum hydride is used for reducing the cinnamyl aldehyde and the evans chiral aid at first, and then addition with metal indium activated 3-propylene bromine is performed to obtain compound shown in a formula 9; the compound shown in the formula 9 isresolved and purified for many times by kinetic resolution; the compound shown in the formula 9 and 2,2-diemthoxy propane can obtain fragment type 10 compound under the pyridinium p-toluenesulfonatecondition, the fragment type 10 compound and fragment type 5 compound can generate olefin metathesis reaction through a Grubbs secondary catalyst, and protecting groups of the fragment type 10 compound are removed under the hydrochloric acid condition to obtain Cryptofolione.

Anti-trypanosome anticancer natural product Cryptofolione synthesizing method

The invention discloses a synthesis method of an intermediate for preparing cephalotaxine. Cyclopentadienylsodium and methyl 3-bromopropionate which are taken as initial raw materials undergo six steps of reactions including nucleophilic addition, hydroboration oxidation, hydroxyl protection, reduction, oxidation and reductive ammoniation to synthesize N-2-(3,4-methylenedioxyphenethyl)-3-(4-methoxymethyl-1-cyclopentenyl-1-propyl)amine. The method can be used as a brand-new synthesis route of the intermediate, and has the advantages of mild reaction conditions, simplicity in operation, cheap and easily available raw materials, and high reaction yield, and experimental verification shows that the total yield of the method can reach 33.4%. In conclusion, the method fills the gap in synthesismethods of the N-2-(3,4-methylenedioxyphenethyl)-3-(4-methoxymethyl-1-cyclopentenyl-1-propyl)amine, and has outstanding technical advantages in the aspects of cost, yield, reaction conditions and thelike.

Synthesis method of intermediate for preparing cephalotaxine

The invention discloses a method for synthesizing weight loss drug orlistat key intermediate. According to the method disclosed by the invention, n-dodecanal is utilized as a beginning raw material, orlistat intermediate compound (9) is prepared through multiple steps of reaction, and finally, orlistat can be prepared through two steps of known reaction of chiral hydroxyl deprotection reaction andmistsunobu reaction. A synthesizing strategy of the method disclosed by the invention is a typical linear strategy, a route design is simple and reasonable, an operation technology is convenient, reaction conditions are moderate, steps are few, a product yield is high, production cost is remarkably reduced, and the method is suitable for industrial preparation.

Synthesizing method of weight loss drug orlistat intermediate

The invention discloses a synthesis method of a natural product cephalotaxine. The purpose of the invention is to provide a brand new synthesis route. Sodium cyclopentadienylide used as an initial rawmaterial undergoes key reaction steps such as a hydroboration oxidation reaction, an iodide ion induced N heterocyclic ring construction reaction and a palladium-catalyzed coupling ring closing reaction to finally achieve formalized synthesis of the natural product cephalotaxine. The method has the advantages of unique and novel design of the synthesis route, mild conditions of the reaction process, high speed, few side reactions, simplicity in operation, and realization of cheap and easily available raw materials and great reduction of the synthesis cost due to conventional chemical reagentsutilized in the route.

Wang Xiaoji

Papers

Green Synthesis of 2‐Substituted Imidazolines using Hydrogen Peroxide Catalyzed by Tungstophosphoric Acid and Tetrabutylammonium Bromide in Water

Anti-trypanosome anticancer natural product Cryptofolione synthesizing method

Synthesis method of intermediate for preparing cephalotaxine

Synthesizing method of weight loss drug orlistat intermediate

Synthesis method of natural product cephalotaxine