6237-59-8Relevant academic research and scientific papers
Pd(0)-catalyzed selective [2 + 2 + 2] cycloaddition of dimethyl nona- 2,7-diyne-1,9-dioate derivatives with dimethyl acetylenedicarboxylate
Yamamoto, Yoshihiko,Nagata, Asako,Itoh, Kenji
, p. 5035 - 5038 (1999)
In the presence of 2.5 mol % of Pd2(dba)3 and 5 mol % of PPh3, nearly equimolar mounts of dimethyl nona-2,7-diyne-1,9-dioate derivatives and dimethyl acetylenedicarboxylate (DMAD) were reacted in toluene at 110 °C to give
Reaktive ?-Komplexe der elektronenreichen Uebergangsmetalle. XIII. (η6-Hexalkylbenzol)(η4-naphthalin)eisen-Komplexe: Synthese, Eigenschaften, Struktur und Reaktivitaet
Brodt, Catherine,Niu, Shuqiang,Pritzkow, Hans,Stephan, Martin,Zenneck, Ulrich
, p. 283 - 292 (1993)
(η6-Hexaalkylbenene)(η4-naphthalene)iron- and (η6-hexaalkylbenzene)(η4-1,4-dimethylnaphthalene)iron-complexes (alkyl=methyl and ethyl) can be prepared from bis(ethylene)(toluene)iron, the desired naphthalene der
Palladium-Catalyzed [3+2] and [2+2+2] Annulations of 4-Iodo-2-quinolones with Activated Alkynes through Selective C?H Activation
Yamamoto, Yoshihiko,Jiang, Jiyue,Yasui, Takeshi
, p. 3749 - 3757 (2020)
The palladium-catalyzed reaction of 4-iodo-2-quinolones with activated alkynes was investigated. Cyclopenta[de]quinoline-2(1 H)-ones and/or phenanthridine-6(5 H)-ones were obtained through [3+2] annulation involving aromatic C?H activation or [2+2+2] annulation involving vinylic C?H activation, respectively. Reasonable mechanisms for the formation of these annulation products have been proposed based on density functional theory calculations.
Unexpected formation and conversion: Role of substituents of 1,3-ynones in the reactivity and product distribution during their reactions with Ru3(CO)12
Xu, Lei,Jiang, Liping,Li, Shasha,Zhang, Guofang,Zhang, Weiqiang,Gao, Ziwei
, p. 1478 - 1486 (2019)
The reactions of Ru3(CO)12 with alkynyl ketones R1CCC(O)R2 (R1 = Et, R2 = Me (1); R1 = Ph, R2 = Me (2); R1 = n-hexyl, R2 = Ph (3); R1 = H, R2 = CH3 (4); and R1 = C(O)OCH3, R2 = OCH3 (5)) proceeds in toluene with the formation of three ruthenoles (1a-3a), four CO-inserted binuclear clusters (1b-2b, 1c and 3c), a tetranuclear cluster 4a, a binuclear cluster 5a and a cyclotrimerization product 5b. Clusters 1a-3a, 1b, 2b, 1c and 3c were isolated from the reactions of Ru3(CO)12 with two equivalents of the corresponding ketones 1-3; 4a and 5a were collected by adding 4 and 5 to Ru3(CO)12 in molar ratios of 1:1 and 1:3, respectively; 5b was obtained by adding 5 to 5a in a molar ratio of 2:1. All compounds were characterized by NMR, FT-IR, and MS-ESI, and most of them were structurally verified by single crystal X-ray diffraction. Although the reaction products of 1-3 and Ru3(CO)12 exhibit similar cluster frameworks of usual ruthenoles and CO-inserted binuclear clusters, the isolation of the clusters 1b-2b, 1c and 3c reveals their strong dependence on both electronic and steric effects of the substituents of the 1,3-ynones 1-3. In addition, detailed investigations suggested that the high reactivity of the terminal hydrogen atom and electron-withdrawing property of the carbonyl group in 4 play a key role in the formation of 4a, and that the structurally unusual 5a is an intermediate in the formation of 5b.
Synthesis of new polycyclic β-lactams via one-pot enyne metathesis and Diels-Alder reactions
Desroy, Nicolas,Robert-Peillard, Fabien,Toueg, Julie,Henaut, Charlotte,Duboc, Romain,Rager, Marie-Noelle,Savignac, Monique,Genet, Jean-Pierre
, p. 2665 - 2672 (2004)
One-pot ring-closing enyne metathesis and Diels-Alder reactions led to efficient synthesis of tricyclic and tetracyclic β-lactams.
Catalytic three-component synthesis of conjugated dienes from alkynes via Pd0, Pd(II), and Pd(IV) intermediates containing 1,2-diimine
Van Belzen,Hoffmann,Elsevier
, p. 1743 - 1745 (1997)
Direct, efficient, selective, and catalytic all describe the synthesis of conjugated dienes from two molecules of alkyne, an organic halide, and tetramethyltin with 1 mol% of a (1,2-diimine)palladium complex in DMF (see the catalytic cycle involving Pd0. Pd(II) and Pd(IV) species on the right) Palladium-phosphane complexes do not catalyze this reaction. Furthermore, 1,4-dihalo-l,3-dienes were synthesized stoichiometrically from alkynes and molecular halogen.
Three-step synthesis of end-substituted pentacenes
Stone, Matthew T.,Anderson, Harry L.
, p. 9776 - 9778 (2007)
(Chemical Equation Presented) A concise, three-step synthesis of 1,4,8,11-substituted 2,3,9,-10-tetrakis(methoxycarbonyl)pentacenes from commercially available 1,2,4,5-tetrakis(bromomethyl)benzene was established. Efficient alkynylation, followed by formation of four fused rings via a zirconacyclopentadiene intermediate, and then oxidation with DDQ gave pentacenes 1a-c. The process was compatible with methyl, phenyl, and trimethylsilyl substituents, which have good solubility in various organic solvents.
Rhodium-catalyzed linear cross-trimerization of two different alkynes with an alkene and two different alkenes with an alkyne
Kobayashi, Masayuki,Tanaka, Ken
, p. 9225 - 9229 (2012)
Crossing paths with rhodium: A cationic RhI/H8-BINAP complex has been found to catalyze the linear cross-trimerization of terminal alkynes, acetylenedicarboxylates, and acrylamides to give substituted trienes. The asymmetric linear c
Reaction of [TpRh(C2H4)2] with Dimethyl Acetylenedicarboxylate: Identification of Intermediates of the [2+2+2] Alkyne and Alkyne–Ethylene Cyclo(co)trimerizations
Bottari, Giovanni,Santos, Laura L.,Posadas, Cristina M.,Campos, Jesús,Mereiter, Kurt,Paneque, Margarita
, p. 13715 - 13723 (2016)
The reaction between the bis(ethylene) complex [TpRh(C2H4)2], 1, (Tp=hydrotris(pyrazolyl)borate), and dimethyl acetylenedicarboxylate (DMAD) has been studied under different experimental conditions. A mixture of products was formed, in which TpRhIspecies were prevalent, whereas the presence of trapping agents, like water or acetonitrile, allowed for the stabilization and isolation of octahedral TpRhIIIcompounds. An excess of DMAD gave rise to a small amount of the [2+2+2] cyclotrimerization product hexamethyl mellitate (6). Although no catalytic application of 1 was achieved, mechanistic insights shed light on the formation of stable rhodium species representing the resting state of the catalytic cycle of rhodium-mediated [2+2+2] cyclo(co)trimerization reactions. Metallacyclopentene intermediate species, generated from the activation of one alkyne and one ethylene molecule from 1, and metallacyclopentadiene species, formed by oxidative coupling of two alkynes to the rhodium centre, are crucial steps in the pathways leading to the final organometallic and organic products.
A Rh(I)-Catalyzed Cascade Cyclization of 1,5-Bisallenes and Alkynes for the Formation of cis-3,4-Arylvinyl Pyrrolidines and Cyclopentanes
Vila, Jordi,Vinardell, Roger,Solà, Miquel,Pla-Quintana, Anna,Roglans, Anna
supporting information, p. 206 - 217 (2021/11/17)
The cascade cyclization reactions of 1,5-bisallenes grant access to a great variety of products by precisely tuning the catalyst system and/or the reagents involved. Herein, we present our findings that 1,5-bisallenes react with two molecules of dimethyl acetylenedicarboxylate to afford, in a completely diastereoselective manner, cis-3,4-arylvinyl pyrrolidines and cyclopentanes. DFT calculations have been used to postulate a mechanism for the developed reaction which encompasses a [2+2+2] cycloaddition reaction of the two alkynes and the external double bond of one allene, followed by a cycloisomerization involving the internal double bond of the second allene. (Figure presented.).
