Pd-Catalyzed Regioselective Hydroesterification of Olefins with 2,2,2-Trifluoroethyl Formate
作者:Jinhua Chen、Minyan Huang、Wenlong Ren、Jianxiao Chu、Yian Shi
DOI:10.1002/ejoc.201901601
日期:2020.3.8
A Pd‐catalyzed regioselectivehydroesterification of olefins with 2,2,2‐trifluoroethyl formate (TFEF) is described. Either linear or branched esters can be selectively obtained with proper ligands in most cases. The reaction process is operationally simple and involves no toxic CO gas.
system to produce ketones and aldehydes, which are poisons for ZN catalytic systems, thus explaining their self‐extinguishing nature. The non‐covalent interaction between the long alkyl chain of the donors with the surface plays a vital role in determining the donors′ self‐extinguishing nature. There is a significant thermodynamic preference for the binding of the donor with the longer alkyl chain at the
Chemoenzymatic Synthesis of Lysophosphatidylnucleosides
作者:Rosa Chillemi、Domenico Russo、Sebastiano Sciuto
DOI:10.1021/jo971826v
日期:1998.5.1
5'-O-Lysophosphatidylnucleosides [5'-O-(1-O-acyl-sn-glycero-3-phosphoryl)nucleosides] were obtained by a two-step chemoenzymatic synthesis. 5'-O-(sn-Glycero-3-phosphoryl)nucleosides (5'-GPNs) were first prepared from a phosphoramidite of 1,2-O-isopropylidene-sn-glycerol and appropriately protected nucleosides, applying the phosphoramidite methodology on the solid phase or in solution. In a following step, the regioselective acylation at the C-l hydroxyl of the glycerol moiety of 5'-GPNs was achieved by a lipase-catalyzed transacylation with activated fatty acid esters in organic solvent. Some deoxyribo- and ribonucleosides, as well, were converted into the corresponding lysophosphatidyl derivatives utilizing either saturated or unsaturated fatty acid esters with different length alkyl chains. The synthesis was also applied to the preparation of O-(1-O-palmitoyl-sn-glycero-3-phosphoryl) conjugates of Acyclovir and AZT, of potential pharmacological interest.
A facile lipase catalyzed access to fatty acid monoesters of
作者:Diego Colombo、Fiamma Ronchetti、Antonio Scala、Ida M. Taino、Lucio Toma
DOI:10.1016/0957-4166(96)00073-0
日期:1996.3
2-O-beta-D-glucopyranosylglycerol was submitted to acylation using Pseudomonas cepacia lipase as catalyst and 2,2,2-trifluoroethyl esters of various long chain carboxylic acids as acyl carriers. Monoacylation was easily accomplished with preferred formation of the (2S)-1-O-acyl derivatives in reactions showing high regio- and diastereoselectivity. (C) 1996 Elsevier Science Ltd