Indanones 2-alkyl-substituted

It has already been seen (see Section II,B and V,E) that vinylketene complexes of cobalt6,95 and chromium22 react with alkynes to produce cyclo-pentadienones, indanones, and substituted phenols. It has been shown108,109,144,145 that similar products may be derived from the alkyne adducts 247. Indeed, when alkyl or aryl substituted alkynes were reacted with vinylketene complex 221.e, a mixture of organic and organometallic products was isolated. In the cases where the alkyne is attached to an aromatic substituent, the expected alkyne adduct (247.h and 247.i) is isolated in low yield. However, when the vinylketene complex was treated... 

Regioselective F-C acylations of carboxylic anhydrides can be accompanied by other Lewis acid mediated reactions in tandem. Recently, a general method for the Lewis acid mediated intramolecular cyclization of keto ester alkyl substituted arenes to functionalized 1-indanones was reported by Pillion. Thus treatment of Meldrum s acid analogue 23 under a variety of... 

Alkylation of 1-indanone with 2-dimethylaminoethyl chloride affords the substituted ketone (1). Condensation with the lithium reagent obtained from 2-ethylpyridine affords the alcohol (2). Dehydration under acidic conditions gives dimethyl-pyrindene (3). ... 

Ceric ammonium nitrate promoted oxidative addition of silyl enol ethers to 1,3-butadiene affords 1 1 mixtures of 4-(/J-oxoalkyl)-substituted 3-nitroxy-l-butene and l-nitroxy-2-butene27. Palladium(0)-catalyzed alkylation of the nitroxy isomeric mixture takes place through a common ij3 palladium complex which undergoes nucleophilic attack almost exclusively at the less substituted allylic carbon. Thus, oxidative addition of the silyl enol ether of 1-indanone to 1,3-butadiene followed by palladium-catalyzed substitution with sodium dimethyl malonate afforded 42% of a 19 1 mixture of methyl ( )-2-(methoxycarbonyl)-6-(l-oxo-2-indanyl)-4-hexenoate (5) and methyl 2-(methoxycarbonyl)-4-(l-oxo-2-indanyl)-3-vinylbutanoate (6), respectively (equation 12). 

Klumpp and co-workers362 have performed a detailed study of the acylation reactions of benzene with a variety of cinnamic acid derivatives in triflic acid. Cinnamic acids with alkyl or weakly electron-withdrawing groups (F, Br) on the phenyl ring give the corresponding substituted indanones as a result of a two-step... 

Asymmetric Alkylation. 7Y-[4-(Trifluoromethyl)benzyl]-cinchoninium bromide (1) has been used as chiral phase-transfer catalyst in the alkylation of indanones (eq 1). For the alkylation of a-aryl-substituted carbonyl compounds the diastere-omeric 7Y-[4-(trifluoromethyl)benzyl]cinchonidinium bromide (2) was used to obtain the opposite stereochemistry (eqs 2 and 3). The asymmetric alkylation of oxindoles was used as the key step in an asymmetric synthesis of (—)-physostigmine (eq 4). ... 

Indanones are very useful and versatile intermediates in the synthesis of metallocene catalysts. Scheme 1 has the synthetic scheme originally used for the preparation of 2-alkyl-4-aryl-substituted ansa metallocenes [9-11]. In the first part of this sequence, the biaryl unit is assembled and the missing carbon atoms are introduced as a side chain. The reaction of 2-phenylbenzyl bromide with malonic acid ethyl ester under basic conditions, followed by a decarboxylation, affords the 2-(2-phenylbenzyl)propionic acid. Chlorination and Friedel-Crafts acylation yields the 2-methyl-4-phenylindanone in 93 % yield. From here, only a few standard transformations are required to complete the synthesis, finally yielding the desired metallocene. 

Chen and coworkers published a formal [3 + 3]-type reaction to give highly substituted cyclohexenes 8. This domino process consists of an allylic-allylic alkylation of an a,a-dicyanoalkene derived from 1-indanone and Morita-Baylis-Hillman carbonates, following an intramolecular Michael addition, by employing dual orga-nocatalysis of commercially available modified cinchona alkaloid (DHQD)2AQN If (hydroquinidine (anthraquinone-l,4-diyl) diether) and (S)-BINOL. The cyclic adducts... 

Bromocamphor has been employed as the chiral starting material in an enantiospecific synthesis (ref. 146) which involved the formation of an indanone (CD moiety) related structurally to that used by Hoffmann-La Roche and led finally to (-)-estrone. Attempts to alkylate the a,p-unsaturated ketone with 2-(3-methoxyphenyl)ethyl iodide failed, not surprisingly, due to an elimination rather than the desired substitution reaction and accordingly the use of an a-methylenic derivative of the ketone and 3-methoxybenzyl chloride were obligatory. By the use of (-)-3-bromocamphor, which is readily available from (-)-borneol by oxidation to (-)-camphor and bromination, natural (+)-estrone could be obtained. 

In middle of the 1980s, efficient asymmetric phase-transfer reactions using catalytic amounts of Al-benzylcinchoninium chlorides were developed by researchers at Merck. This catalyst was able to alkylate 2-substituted-2-phenyl indanones with high ee (up to 94% ee) [20]. 

More recently, the cyclizations of 2-alkyl-1-ethynylbenzenes to 1-substituted-l//-indenes and 1-indanones have also been developed (Scheme 45) [159],... 

The highly electrophilic cationic bis(8-quinolinolato)aluminum complex 407 enabled Yamamoto and coworkers to perform Mukaiyama-Michael additions of silyl enol ethers to crotonylphosphonates 406. The procedure was not only applicable to enol silanes derived from aryl methyl and alkyl methyl ketones (a-unsubstituted silicon enolates) but also to several cycfic a-disubstituted silyl enol ethers, as illustrated for the derivatives of a-methyl tetralone and indanone 405 in Scheme 5.105. Despite the steric demand of that substitution pattern, the reaction occurred in relatively high chemical yield with varying diastereoselectivity and excellent enantiomeric excess of the major diastereomer. The phosphonate residue was replaced in the course of the workup procedure to give the methyl esters 408. The protocol was extended inter alia to the silyl enol ether of 2,6,6-tetramethylcyclohexanone. The relative and absolute configuration of the products 408 was not elucidated [200]. 

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