This study concerns the structural change of lignin during auto-catalyzed ethanol-water pulping of aspen by 1H-NMR. The results showed that the linkages of alkyl-aryl ether of lignin, such as the α-ether linkages (α-O-4) and the β-ether linkages (β-O-4), were broken and the alkyl part formed carbenium at the Cα and Cβ of the aliphatic branch. Meanwhile, the aryl part of ether accepted one H and...

Cross-electrophile coupling, the cross-coupling of two different electrophiles, avoids the need for preformed carbon nucleophiles, but development of general methods has lagged behind cross-coupling and C-H functionalization. A central reason for this slow development is the challenge of selectively coupling two substrates that are alike in reactivity. This Account describes the discovery of ge...

< p>In this communication, we have reported that the Pd(OAc)2–Et3SiH-DMF system promotes the microwave-assisted chemoselective reduction of aryl α,β-unsaturated esters in good yields. The protocol affords a convenient reduction of aryl-conjugated double bonds even in presence of other functional groups like esters, phenols, and ethers.

tert-Butoxyacetylene is shown to undergo Sonogashira coupling with aryl iodides to yield aryl-substituted tert-butyl ynol ethers. These intermediates participate in a [1,5]-hydride shift, which results in the extrusion of isobutylene and the generation of aryl ketenes. The ketenes are trapped in situ with multiple nucleophiles or undergo electrocyclic ring closure to yield hydroxynaphthalenes a...

A bidentate nitrogen-donor ligand with an appended phenol group, C5H4NCH[double bond, length as m-dash]N-2-C6H4OH, H(L1) was treated with a palladium cycloneophyl complex [Pd(CH2CMe2C6H4)(COD)], with both Pd-aryl and Pd-alkyl bonds, to give a Pd-alkyl complex, [Pd(CH2CMe2C6H5)(κ3-N,N',O-OC6H4N[double bond, length as m-dash]CH(2-C5H4N))], 1. The cleavage of the Pd-aryl bond and the deprotonation...

the synthesis of a novel class of 2-oxoindolin-3-ylidene-(1-arylhydrazinyl)-2-aryl(alkyl)ethylidene derivativesvia a copper-catalyzed tandem reaction of isatin, arylhydrazines, sulfonyl azides and terminal alkynes is described.

Silica chloride converted benzyl or tert-butyl esters to the corresponding acid chlorides and alkyl chlorides. It also converted benzyl or tert-butyl phenyl ethers to the corresponding allcyl chlorides and phenol

Microsomal enzymes from Ehrlich ascites tumors synthesized 0-alkyl glyceryl ethers from hexadecanol and dihydroxyacetone phosphate in the presence of ATP, CoA, and Mg++. Glyceryl ether synthesis occurred via the formation of 0-alkyldihydroxyacetone phosphate and O-alkyldihydroxyacetone. Although NADPH inhibited the initial reaction of dihydroxyacetone phosphate with fatty alcohol, it was requir...

Simple iron salts such as FeCl(n), Fe(acac)(n) (n = 2,3) or the salen complex 4 turned out to be highly efficient, cheap, toxicologically benign, and environmentally friendly precatalysts for a host of cross-coupling reactions of alkyl or aryl Grignard reagents, zincates, or organomanganese species with aryl and heteroaryl chlorides, triflates, and even tosylates. An "inorganic Grignard reagent...

Hydrogen iodide, generated (and regenerated) in situ by the action of iodine upon hypophosphorous acid, was found to reduce a variety of aryl carbinols to the corresponding diphenylmethanes under mild conditions. The generality of the reaction was explored by extension to several diols, heterocyclic alcohols, and allylic alcohols. Several lines of evidence, including occasional isolation of alk...