Synthesis of [1]benzopyrano[4,3-b]pyrrol-4(1H)-ones from N(α)-(2-oxo-2H-1-benzopyran-4-yl)weinreb α-aminoamides
作者:Angel Alberola、Rocío Álvaro、Alfonso González Ortega、M.Luisa Sádaba、M Carmen Sañudo
DOI:10.1016/s0040-4020(99)00802-9
日期:1999.11
were prepared from 4-chlorocoumarin and α-aminoacid derivatives. Their reaction with organometallic compounds (RLi or RMgBr) and subsequent cyclization of ketones thus obtained, give [1]benzopyrano[4,3-b]pyrrol-4(1H)-ones. Starting from proline derivatives, simultaneously with the pyranone-pyrrole fusion, we establish an interesting procedure for the formation of pyrrolizines.
由4-氯香豆素和α-氨基酸衍生物制得N(α)-(2-Oxo-2 H -1-苯并吡喃-4-基)Weinreb-α-氨基酰胺。它们与有机金属化合物(RLi或RMgBr)反应,然后将如此得到的酮环化,得到[1]苯并吡喃并[4,3 - b ]吡咯-4(1 H)-。从脯氨酸衍生物开始,与吡喃酮-吡咯融合同时,我们建立了一个有趣的过程,用于形成吡咯嗪。
Ruthenium Catalyzed Dehydrogenation of Alcohols and Mechanistic Study
作者:Mahendra K. Awasthi、Sanjay K. Singh
DOI:10.1021/acs.inorgchem.9b02691
日期:2019.11.4
We synthesized pyridylamine ligated arene-Ru(II) complexes and employed these complexes for the catalytic acceptorless dehydrogenation of primary alcohols to carboxylic acids. All the synthesized complexes [Ru]-1–[Ru]-10 are characterized using several spectro-analytical techniques, and the structures of complexes [Ru]-1, [Ru]-2, and [Ru]-5 are determined using single crystal X-ray crystallography
RUTHENIUM COMPLEXES AND THEIR USES AS CATALYSTS IN PROCESSES FOR FORMATION AND/OR HYDROGENATION OF ESTERS, AMIDES AND RELATED REACTIONS
申请人:YEDA RESEARCH AND DEVELOPMENT CO. LTD.
公开号:US20170283447A1
公开(公告)日:2017-10-05
The present invention relates to novel Ruthenium complexes of formulae A1-A4 and their use, inter alia, for (1) dehydrogenative coupling of alcohols to esters; (2) hydrogenation of esters to alcohols (including hydrogenation of cyclic esters (lactones) or cyclic di-esters (di-lactones), or polyesters); (3) preparing amides from alcohols and amines—(including the preparation of polyamides (e.g., polypeptides) by reacting dialcohols and diamines and/or polymerization of amino alcohols and/or forming cyclic dipeptides from p-aminoalcohols; (4) hydrogenation of amides (including cyclic dipeptides, polypeptides and polyamides) to alcohols and amines; (5) hydrogenation of organic carbonates (including polycarbonates) to alcohols or hydrogenation of carbamates (including polycarbamates) or urea derivatives to alcohols and amines; (6) dehydrogenation of secondary alcohols to ketones; (7) amidation of esters (i.e., synthesis of amides from esters and amines); (8) acylation of alcohols using esters; (9) coupling of alcohols with water and a base to form carboxylic acids; and (10) preparation of amino acids or their salts by coupling of amino alcohols with water and a base. The present, invention further relates to the use of certain known Ruthenium complexes for the preparation of amino acids or their salts from amino alcohols.
The gem-dimethyl effect on reactivities in cyclizations through tetrahedral intermediates. Cyclization of methyl-substituted methyl amides of 5-(p-nitrophenyl)hydantoic acids
作者:Asen H. Koedjikov、Iva B. Blagoeva、Ivan G. Pojarlieff、Anthony J. Kirby
DOI:10.1039/p29960002479
日期:——
At high pH the tetrahedralintermediate is in equilibrium with the reactants and the rate is limited by proton transfers producing T±. The accelerations upon methyl substitution vary strongly with the various processes observed and may be explained in terms of a general gem-dimethyl effect increasing along the reaction coordinate from reagent through cyclic tetrahedralintermediate to final ring product