104-62-1Relevant articles and documents
Facile deallylation protocols for the preparation of N-unsubstituted triazoles and tetrazoles
Kamijo, Shin,Huo, Zhibao,Jin, Tienan,Kanazawa, Chikashi,Yamamoto, Yoshinori
, p. 6389 - 6397 (2005)
Two facile deallylation protocols have been developed for the preparation of N-unsubstituted triazoles and tetrazoles. The first protocol is a direct deallylation using a combination of a catalytic amount of nickel complex, NiCl2(dppe), and a stoichiometric amount of Grignard reagent, tBuMgCl. The second protocol is a stepwise deallylation through consecutive reactions of isomerization and ozonolysis. The isomerization from N-allylazoles to N-vinylazoles is catalyzed by a ruthenium complex, HRuCl(CO)(PPh3)3, and the following ozonolysis of the derived N-vinyl intermediates affords N-unsubstituted azoles. These protocols can be used complementarily depending on the type of functional groups in the parent allylated azoles.
Polyvinylpolypyrrolidoniume tribromide as new and metal-free catalyst for the formylation and trimethylsilylation of hydroxyl group
Ghorbani-Choghamarani, Arash,Goudarziafshar, Hamid,Zamani, Parisa
, p. 1207 - 1210 (2011)
Trimethylsilylation of alcohols was achieved using 1,1,1,3,3,3- hexamethyldisilazane (HMDS) as silylating agent, in the presence of polyvinylpolypyrrolidoniume tribromide in acetonitrile at room temperature. Also a variety of alcohols were converted into alkyl formates by ethyl formate and a catalytic amount of polyvinylpolypyrrolidoniume tribromide under solvent free conditions at room temperature.
Tandem Acid/Pd-Catalyzed Reductive Rearrangement of Glycol Derivatives
Ciszek, Benjamin,Fleischer, Ivana,Kathe, Prasad,Schmidt, Tanno A.
, p. 3641 - 3646 (2020/03/25)
Herein, we describe the acid/Pd-tandem-catalyzed transformation of glycol derivatives into terminal formic esters. Mechanistic investigations show that the substrate undergoes rearrangement to an aldehyde under [1,2] hydrogen migration and cleavage of an oxygen-based leaving group. The leaving group is trapped as its formic ester, and the aldehyde is reduced and subsequently esterified to a formate. Whereas the rearrangement to the aldehyde is catalyzed by sulfonic acids, the reduction step requires a unique catalyst system comprising a PdII or Pd0 precursor in loadings as low as 0.75 mol % and α,α′-bis(di-tert-butylphosphino)-o-xylene as ligand. The reduction step makes use of formic acid as an easy-to-handle transfer reductant. The substrate scope of the transformation encompasses both aromatic and aliphatic substrates and a variety of leaving groups.
Efficient Enzymatic Preparation of Flavor Esters in Water
Perdomo, Igor Chiarelli,Gianolio, Stefania,Pinto, Andrea,Romano, Diego,Contente, Martina Letizia,Paradisi, Francesca,Molinari, Francesco
, p. 6517 - 6522 (2019/06/20)
A straightforward biocatalytic method for the enzymatic preparation of different flavor esters starting from primary alcohols (e.g., isoamyl, n-hexyl, geranyl, cinnamyl, 2-phenethyl, and benzyl alcohols) and naturally available ethyl esters (e.g., formate, acetate, propionate, and butyrate) was developed. The biotransformations are catalyzed by an acyltransferase from Mycobacterium smegmatis (MsAcT) and proceeded with excellent yields (80-97%) and short reaction times (30-120 min), even when high substrate concentrations (up to 0.5 M) were used. This enzymatic strategy represents an efficient alternative to the application of lipases in organic solvents and a significant improvement compared with already known methods in terms of reduced use of organic solvents, paving the way to sustainable and efficient preparation of natural flavoring agents.
