Ivanov reagents

This procedure is an adaption of one described by Hauser and Chambers. Previous preparations include the benzylation of diethyl phenylmalonate followed by hydrolysis, the benzylation of phenylacetonitrile followed by hydrolysis, the benzylation of phenylacetic acid through the Ivanov reagent, and the reduction of oi-phenylcinnamic acid using sodium amalgam. ... 

Isosteric equivalence, 77, 149 benzene and thiophene, 52 carbon and nitrogen, 399 Isothiouronium salts, as source of thiols, 44 Isothipendyl, 430 Isoxazole synthesis, 126 Isoxsuprine, 69 Ivanov reagent, 92, 93... 

A few years ago, Blagonev and Ivanov described the bis-deprotonation of aryl acetic acids by Grignard reagents. These magnesinm dianions, known as Ivanov reagents, react with aldehydes and ketones. Reaction between dianions of phenylacetic acid and benzaldehyde yields the anti S-hydroxy acid as the major diastereomer anti/syn 69/22) (equation 113). This result is in agreement with the formation of a cyclic chair-like transition state according to the model of Zimmerman-Traxler . 

Ivanov Reagents are carboxylate enolates (enediolates, or carboxyl 0 acid dianions) derived from phenyl acetic acid or... 

It should be noted that the reaction of acids such as phenylacetic acid with two equivalents of a Grignard reagent gives Ivanov reagents , ArC=C(OMgX)2 [17].)... 

Ivanov reagent. Reaction product of aryl acetic acids and excess Grignard reagent. The reagent may be used in condensations with carbonyl compounds and other Grignard-type reactions. 

Reaction at Benzylic Positions. - The Ivanov reagent obtained... 

The interaction between the sodium salt of phenylacetic acid and isopropyl magnesium bromide results into a doubly charged species known as the Ivanov reagent. This product on treatment with cyclopentanone affords aldol condensation to yield the corresponding hydroxy acid. The resulting product on being subjected to alkylation with N-(2-chloro-ethyl)-dimethylamine gives the desired official compound. 

The addition of enediolates of aryl acetic acids (Ivanov reagents) to electrophiles, particularly carbonyl compounds ... 

Isoxazoline oxides 11, 865 Isoximes s. Nitrones Ivanov reagent 12, 725... 

The most widely accepted transition state model of the aldol addition is the Zimmerman-Traxler model [72]. Originally postulated in a seminal paper dating from 1957 for the addition of Ivanov reagents [73] - dianions of phenylacetic acid with MgX as counterions (cf. Section 2.1) - to benzaldehyde, the model postulates a sbc-membered chair-like transition state. This hypothesis was adapted to a numerous aldol additions performed with a large variety of enolates of hthium, boron, and other metals. The strength of this model is a convincing explanation for the cis-syn, trans-anti correlation, as outlined in Scheme 4.30. 

Phenylacetonitrile allowed to react with isopropylmagnesium bromide in ether, then treated with benzophenone adduct. Y 40-63% 11% via the Li-compound. - The intermediate has a formal similarity to the Ivanov reagent (s. Synth. Meth. 12, 725). F. e. and procedures s. E. M. Kaiser and G. R. Hauser, Am. Soc. 89, 4566 (1967). 

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