Indanes 4-functionalized

Hydrolysis of dimethyl 3-methyl-3//-3-benzazepine-2,4-dicarboxyiate (3) with 50% sulfuric acid, or with 20% hydrochloric acid, effects loss of the nitrogen function and formation of the indane-2-carboxylic acid 4.25... 

Further studies were carried out with halocarbene amides 34 and 357 Although again no direct spectroscopic signatures for specifically solvated carbenes were found, compelling evidence for such solvation was obtained with a combination of laser flash photolysis (LFP) with UV-VIS detection via pyridine ylides, TRIR spectroscopy, density functional theory (DFT) calculations, and kinetic simulations. Carbenes 34 and 35 were generated by photolysis of indan-based precursors (Scheme 4.7) and were directly observed by TRIR spectroscopy in Freon-113 at 1635 and 1650 cm , respectively. The addition of small amounts of dioxane or THF significantly retarded the rate of biomolecular reaction with both pyridine and TME in Freon-113. Also, the addition of dioxane increased the observed lifetime of carbene 34 in Freon-113. These are both unprecedented observations. 

John Ward has functionalized an indane using method D in route to tetra-petalone A (46) (Fig. 4.24).25 The o-OBoc benzyl alcohol 44 undergoes addition with two equivalents of Grignard and affords after acidic workup the phenolic indane 45 in 73% yield. Because of steric effects, only one diastereomer is observed after hydrolysis of the enol ether and thermodynamic equilibration of the... 

Antagonists of metabotropic glutamate receptors and G-protein-coupled receptors associated with various neurodegenerate diseases have been prepared by proline-catalyzed direct a-amination reactions (Scheme 2.30) [7c]. Both, indane carbaldehyde 10 and analogous compounds having an ester functionality [leading to l-aminoindan-l,5-dicarboxylic acid (AIDA)] and or a phosphonate substituent [(RS)-l-amino-5-phosphonoindan-l-carboxylic acid APICA], all reacted with di-... 

The methodology was useful for the preparation of functionalized benzo-fused carbo-cycles. Isomerically pure 4-substituted indans, 209, could be synthesized by cyclization... 

The intramolecular carbolithiation of carbon—carbon double bonds is an interesting route to functionalized carbocyclic and heterocyclic systems that has been developed in the past years and widely used in organic synthesis. In this context, aryllithiums have been described to carbometalate double bonds allowing the preparation of indanes,... 

In light of the facile 5-exo-dig carbolithiation reaction of simple acetylenic alkyllithiums, Bailey and Longstaff have studied the analogous 5-exo cyclization of a benzyne-tethered alkyllithium. Regioselectively 4-functionalized indanes 281 have been prepared... 

Benzylic functionalization. The reaction ol (toIuene)Cr(CO), (1) with KOC(CH,), and ethyl oxalate in DMSO results in the stable enol 2 in 78% yield. Similar products are formed from the reactions of (m-xylene)Cr(C()), and of (indane)Cr(CO),.-... 

However, the equilibrium monomer concentrations of disubstituted alkenes is measurable. The equilibrium constants for dimerization, tri-merization, and polymerization of a-methylstyrene have been determined as a function of temperature under anionic conditions [12] similar values should be obtained under cationic conditions. Unfortunately, the equilibrium position can t be determined directly under cationic conditions due to the irreversible side reactions of isomerization and indan and spirobiindan formation (Section II. A). The equilibrium monomer concentrations of isobutene and isopropenyl vinyl ethers should also be relatively high, albeit lower than those of a-methylstyrenes. However, the true equilibrium can t be reached with these monomers due to irreversible side reactions, and reliable data are therefore not available. Nevertheless, the ceiling temperature of isobutene polymerization is apparently between 50 and 150° C. 

Figure 2.7 contains plots of repetitive injection GC/MS chromatographic peak areas (integrated total ion current) as a function of sample temperature for benzene and styrene as well as selected products representing alkyl aromatics (ethyl benzene), indanes (methyl indane) and indenes (indene) evolved from PS-catalyst samples. The plots show that benzene is by far the most abundant volatile product. All of the PS-catalyst samples produce alkyl benzenes and indanes, however samples containing HZSM-5 catalyst generate significantly lower relative yields of these products. 

To overcome these obstacles, we turned our attention to novel approaches to benzazepine 6 that did not involve benzonorbomadiene and obviated the problems presented by cyclopentadiene generation and oxidative cleavage chemistry (Figure 3.8). Both the Mazzocchi and discovery syntheses generated 1,3-indane dicarbonyl intermediates that were converted to the bicyclic aryl piperidine nucleus. We therefore focused on alternative indane syntheses to access this functionality, targeting readily available synthetic precursors. 

Substituted diazo indan-l,3-diones (143, R = H, 75%, R = Br 84%) and 1,3-diketone 144 are prepared using clays in superior yield. 57,58 Transfer of the diazo function to stereoisomeric cis- or trans-4,6-di-t-Bu-I,3-cyclohexanedione (145) is achieved using TsN3 and KF as base in the hindered ketone side reaction, formation of azine is... 

Cyclizations. Indanes and indolines are readily formed by treatment of 3-butenylarenes and A-allylaniline derivatives with a stoichiometric amount of dilauroyl peroxide. Formation of a seven-membered ring adjoining an existing aromatic nucleus by radical cyclization of xanthate precursors has a useful scope. Several different functional groups inside the chain are tolerated. 

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