74726-76-4Relevant academic research and scientific papers
Synthesis of [6,6,m]-Tricyclic Compounds via [4+2] Cycloaddition with Au or Cu Catalyst
Kang, Juyeon,Ham, Seunghwan,Seong, Chaehyeon,Oh, Chang Ho
, p. 1039 - 1043 (2021/05/05)
We synthesized [6,6,6]- and [6,6,7]-tricyclic compounds via intramolecular [4+2] cycloaddition by gold or copper catalysts. Substrates for cyclization were prepared by coupling reactions between eight types of diyne and four types of aromatic moieties. We have successfully synthesized eleven tricyclic compounds.
Metal- and Hydride-Free Pentannulative Reductive Aldol Reaction
Satpathi, Bishnupada,Dutta, Lona,Ramasastry
supporting information, p. 170 - 174 (2019/01/04)
Traditionally, the reductive aldol reaction is a metal-catalyzed and hydride-promoted coupling between enones and aldehydes. We present a phosphine-mediated diastereoselective intramolecular reductive aldol reaction of α-substituted dienones and aldehydes, which is metal-free and hydride-free. The synthetic utility of the reductive aldol adducts is demonstrated by elaborating them in one step to indeno[1,2-b]furanones, indeno[1,2-b]pyrans, and dibenzo[a,h]azulen-8-ones.
Regioselective bromination: An approach to the D-ring of the gilvocarcins
Sharif, Ehesan U.,O'Doherty, George A.
, p. 1275 - 1285 (2016/11/11)
A method for the regioselective ortho-bromination of unsymmetrically protected 3,5-dihydroxybenzoic acid esters has been developed. The route involves protecting group optimization studies to attain high regioselectivity for the ortho-bromination. Pd-catalyzed stannation and boration were performed to construct the D-ring coupling partners for the synthesis of gilvocarcin analogs.
Pd-catalyzed direct arylation approach to the 6H-dibenzo[c,h]chromenes: Total synthesis of arnottin I
De, Subhadip,Chaudhuri, Saikat,Mishra, Sourabh,Mamtani, Himanshu,Bisai, Alakesh
, p. 1871 - 1884 (2014/01/17)
An efficient synthesis of 6H-dibenzo[c,h]chromenes has been achieved from 2-bromobenzyl-α-naphthyl ethers via a Pd-catalyzed Intramolecular direct-arylation using easily available Pd(PPh3)4 or Pd(OAc)2/PPh3 at elevated temperature. The reaction affords biaryl-coupling products in good to excellent yields in 6-9 h (up to 94% yields). A tentative mechanism has been proposed to understand the reaction pathway. Applying the methodology, a straightforward and concise total synthesis of arnottin I has been demonstrated by converting the biaryl-coupling products to the 6H-benzo[d]naphtho[1,2-b]pyran-6-one using pyridinium chlorochromate (PCC) mediated oxidation.
Discovery and synthesis of new immunosuppressive alkaloids from the stem of Fissistigma oldhamii (Hemsl.) Merr.
Zhang, Yi-Nan,Zhong, Xiang-Gen,Zheng, Zong-Ping,Hu, Xu-Dong,Zuo, Jian-Ping,Hu, Li-Hong
, p. 988 - 996 (2007/10/03)
Three new alkaloids (1-3) and twenty-one known compounds were isolated from the stem of Fissistigma oldhamii (Hemsl.) Merr. which was the ruler herb in an approved Traditional Chinese herbal formula used for treatment of rheumatoid arthritis in China and synthesis of one new immunosuppressive alkaloid was achieved. These compounds, including the crude extracts of this herb, exhibited strong activities in the inhibition of T and B cell proliferation.
Syntheses of mycophenolic acid and its analogs by palladium methodology
Lee,Fujiwara,Ujita,Nagatomo,Ohta,Shimizu
, p. 1437 - 1443 (2007/10/03)
Syntheses of mycophenolic acid (MPA, 1) and its analogs were carried out using palladium-catalyzed Heck carbonylation and olefination. Thus, the reaction of 2-bromo-3,5-dimethoxybenzyl alcohol (4) in toluene under carbon monoxide at 180 °C in the presence of palladium catalyst using sodium carbonate as a base gave 5,7-dimethoxyphthalide (5) in 88% yield. The phthalide 7 was converted to 6-iodo-5,7-dimethoxy-4-methylphthalide (8). Reaction of aromatic iodide 8 with isoprene and dimethyl malonate in the presence of palladium(0) catalyst gave the three component coupling product 9, which was converted into 1 in three steps. 4-NorMPA (16) and 4-homoMPA (22) were synthesized similarly.
Regioselectivity in the Lithiation of 1,3-Disubstituted Arenes
Baker, Robert W.,Liu, Song,Sargent, Melvyn V.,Skelton, Brian W.,White, Allan H.
, p. 831 - 840 (2007/10/03)
The regioselectivity of the lithiation of 1,4,5,8-tetramethoxynaphthalene-2-carbaldehyde (7) with butyllithium or phenyllithium in the presence of N,N,N′-trimethylethylenediamine and the subsequent bromination of the lithiated species so generated with 1,2-dibromotetrafluoroethane were investigated. Similar investigations with butyllithium as base in the presence of N,N,N′,N′-tetramethylethylenediamine or potassium t-butoxide were carried out on 1,4,5,8-tetramethoxynaphthalene-2-methanol (14). These studies were extended to 1,5,8-trirnethoxynaphthalene-3-methanol (25), 3-methoxybenzenemethanol (29) and 3,5-dimethoxybenzenemethanol (32). The X-ray crystal structure of 6-bromo-1,4,5,8-tetramethoxynaphthalene-2-methanol (17) is described.
The first synthesis of C-terminal biphenyl moiety of vancomycin
Rama Rao,Chakraborty,Joshi
, p. 4045 - 4048 (2007/10/02)
A successful Palladium catalysed intramolecular coupling of phenyl rings corresponding to amino acids (R)-4-hydroxyphenylglycine and (S)-3,5-dihydroxyphenylglycine of vancomycin is achieved.
A GENERAL SYNTHETIC METHOD FOR ORSELLINIC ACID MOIETY OF MACROLIDES BY THE PALLADIUM-CATALYZED CARBONYLATION OF ARYL IODIDE AND ITS APPLICATION TO ZEARALENONE SYNTHESIS
Takahashi, Takashi,Nagashima, Toshiharu,Tsuji, Jiro
, p. 369 - 372 (2007/10/02)
Palladium-catalyzed carbonylation of 1-iodo-2-phenylthiomethyl-4,6-dimethoxybenzene (9) with 10-iodo-6,2'-dioxolane-2-decanol (10) afforded the corresponding ω-iodoalkyl ester of 2-phenylthiomethyl-4,6-dimethoxybenzoate (3) in 70percent yield, which
