27436-93-7Relevant articles and documents
A four-step route to synthetic equivalents of ortho-xylylenes: D?tz benzannulation, desilylation, bromo-dehydroxylation, and sultine formation. A concise approach to oxygenated linearly fused polycyclic aromatics
Kotha, Sambasivarao,Aswar, Vikas R.,Manchoju, Amarender
, p. 2306 - 2315 (2016)
A new route has been reported for the synthesis of densely oxygenated polycyclic aromatic compounds via cycloaddition approach. This strategy involves the D?tz benzannulation and Diels-Alder reaction as key steps. Naphthalene synthons required here were g
Coupling of Cyclobutenediones with Fischer Carbene Complexes: A One-Step Synthesis of Cyclopentenediones and/or 5-Alkylidenefuranones via Net Insertion of the Carbene Unit into a C - C Bond
Zora, Metin,Li, Yuhui,Herndon, James W.
, p. 4429 - 4436 (1999)
The reaction of Fischer carbene - chromium complexes with 3-cyclobutene-1,2-diones has been investigated. In most cases, the major product of the reaction is the C - C bond insertion product, a 2-alkoxy-4-cyclopentene-1,3-dione, accompanied by a minor amount of the partial deoxygenation product, a 4-cyclopentene-1,3-dione. In some cases, 5-alkylidenefuranones are also formed. A mechanism involving oxidative addition of the coordinatively unsaturated Fischer carbene complex followed by acyl migration and reductive elimination was proposed to account for cyclopentenedione formation. Furanone formation was thought to arise via demetalation of the acyl migration product, followed by O-acylation. An electronic dependence was noted for cyclopentenedione/alkylidene - furanone ratio, which was evaluated using the Hammett equation.
Preparation of Fischer carbene complexes by alkylation of acylmetalates with alkyl iodides
Hoye, Thomas R.,Chen, Kejian,Vyvyan, James R.
, p. 2806 - 2809 (1993)
Neutral Fischer carbene complexes bearing alkoxy groups as the donor substituents on the carbene carbon atom have been synthesized by direct alkylation of the lithium acylmetalates (formed by classical addition of organolithium compounds to metal hexacarbonyl) by alkyl iodides. It was shown that the reaction proceeds under normal phase-transfer conditions (CH2-Cl2/H2O) or, preferably, in aqueous medium alone. However, in both cases the presence of a catalytic amount of a tetraalkylammonium salt (n-Bu4NBr) was required. Attractive features of this methodology are (i) the economy of using alkyl iodides in place of the usual alkylating agents (like Me3O+BF4-, magic methyl, or methyl triflate), (ii) the procedural ease of one-pot preparation of the carbene complexes, and (iii) the greater variety of alkyl moieties that can be incorporated as part of the alkoxy substituent using the more readily available alkyl iodides containing nontrivial alkyl groups. The procedure is preparatively useful for accessing chromium-containing carbenes, but yields of the analogous molybdenum- and tungsten-containing species are only ≤10%. Mechanistic considerations suggest that products are formed by competing pathways involving direct SN2 displacement vs electron-transfer-initiated SRN1 processes.
Physical organic chemistry of transition metal carbene complexes. 19. Kinetics of reversible alkoxide ion addition to substituted (methoxyphenylcarbene)pentacarbonylchromium(0) and (methoxyphenylcarbene)pentacarbonyltungsten(0) in methanol and aqueous ace
Bernasconi, Claude F.,Garcia-Rio, Luis
, p. 3821 - 3829 (2007/10/03)
Rate and equilibrium constants for the nucleophilic addition of MeO- in methanol and in 90% MeCN-10% MeOH, of HC≡CCH2O- and CF3CH2O- in 50% MeCN-50% water, and of OH- in 50% MeCN
