Polyvalent iodine in synthesis. 1. An efficient route to isopropylidene arylmalonates (5-aryl-substituted Meldrum's acid)

Abstract

fashion to that described above, to provide a hydrocarbon (0.32 g, 73%). On GLC analysis the mixture was found to contain two components with retention times of 18.91 and 19.55 min in the ratio 21.2:78.8 (column A; oven temperature 100 °C, 10 min-5°/min-250 °C), respectively. From GC/MS data and the 13C NMR (CDC13) spectrum, the oil was found to contain the less symmetrical alkene as the minor component (15-20%) and the more symmetrical alkene as the major isomer. 8]tetradec-4-ene:

Highly Efficient Arylation of Malonates with Diaryliodonium Salts

“…The analytical GLC to determine the product ratios was carried out with a Hewlett-Packard 5880A gas chromatography employing a DB-1 bonded-phase methylsilicon capillary column and flame-ionization detector. All products were purified by flash chromatography using silica gel 60 (70−230 mesh, Merck) and identified with 1 H and 13 C NMR spectral data obtained from a Varian Unity 300 MHz NMR spectrometer using tetramethylsilane as an internal standard. , …”

“…Recently, high valent iodonium salts have been revisited as reactive aryl iodide equivalents in organic reactions . In early studies on high valent iodonium salts, some keto enolates reacted with diaryliodonium salts to give arylated ketones in good yields, but ester enolates with the iodonium salts afforded the arylated esters only in low to moderate yields, although the nucleophilicities of keto and ester enolates are almost identical. During our total synthesis of sesquiterpene laurene and its analogues, we needed an efficient arylation methodology that could access structurally diverse arylated malonate esters.…”

Advances in Synthetic Applications of Hypervalent Iodine Compounds

“…Diaryliodonium salts are effective electrophilic arylating reagents toward various carbon nucleophiles and, in particular, have been used for mono- or diarylations of carbonyl compounds. − Gaunt and co-workers have reported the N -heterocyclic carbene 432 -mediated C–H bond arylation of aldehyde 430 with diaryliodonium salt 431 giving heteroaryl ketone 433 . This new strategy provides a synthetic approach to various ketones bearing a diverse array of aryl and heteroaryl substituents that can subsequently be converted into molecules displaying structural motifs commonly found in medicinal agents (Scheme ).…”

Diaryliodonium Salts: A Journey from Obscurity to Fame

“…[90] Similar conditions were employed by Chen and co-workers in the arylation of Meldrums acid. [91] An alternative method for the arylation of diones was published by Hampton and co-workers, in which phenyl-2,4-pentanedione was prepared using sodamide in liquid ammonia. [92] It was possible to conduct this reaction on a multigram scale, furnishing the product in up to 64 % yield.…”