10.1039/b915533c
The research proposes O-silylated C3-halohydrins as novel protected building blocks for the total, regio-, and stereocontrolled synthesis of glycerolipid frameworks. The purpose is to develop efficient methods for synthesizing various glycerolipids with specific structures, which are important for biochemical and pharmacological studies. Key chemicals include O-silylated C3-halohydrins such as 1(3)-O-silyl-2-O-acyl-, 1,2(2,3)-O-bis(silyl)-, and 1(3)-O-acyl-2-O-silyl-3(1)-halo-sn-glycerides. These compounds allow for the displacement of iodine by carboxylates, selective acylation, direct exchange of O-silyl protection for trichloroacetyl groups, and conversion of TBDMS groups into trifluoroacetates without affecting other functional groups. The methodology is entirely regio- and stereospecific, avoiding acyl migration and providing target compounds with chosen absolute configurations from a single synthetic precursor. The research concludes that this new strategy is high yielding, minimizes synthetic operations, and can be easily scaled up, offering a powerful method for the preparation of di- and triacylglycerols as well as glycerol-based cationic lipids.
10.1002/cssc.201500053
The research focuses on the development and evaluation of a Pd/Nb2O5/SiO2 catalyst for the direct hydrodeoxygenation (HDO) of biomass-derived compounds into liquid alkanes under mild conditions. The study involves the conversion of model compounds such as 4-(2-furyl)-3-buten-2-one (derived from furfural and acetone), palmitic acid, tristearin, and diphenyl ether, which represent microalgae oils, vegetable oils, and lignin, respectively. The experiments utilize a Pd-loaded Nb2O5/SiO2 catalyst prepared via a sol-gel method, aiming to achieve high yields of alkanes with minimal C-C bond cleavage. The catalyst's performance is assessed through batch reactions in a stainless-steel autoclave under controlled temperature (170°C) and pressure (2.5 MPa H2), with product analysis conducted using GC-MS to quantify the liquid products against an internal standard. The research also includes characterization of the catalyst using techniques like XRD, N2 adsorption-desorption isotherms, TEM, and EDAX atomic mapping to understand its structure and active sites. The study demonstrates that the Pd/10%Nb2O5/SiO2 catalyst is highly effective, achieving over 94% yield of alkanes under the specified mild conditions, and exhibits excellent stability and activity, making it a promising candidate for biomass conversion to liquid alkanes.
