56930-52-0Relevant academic research and scientific papers
Divergent Reactivity of α,α-Disubstituted Alkenyl Hydrazones: Bench Stable Cyclopropylcarbinyl Equivalents
Ritchie, Nina F. C.,Zahara, Adam J.,Wilkerson-Hill, Sidney M.
, p. 2101 - 2106 (2022/02/14)
Herein we report the divergent reactivity of 2,2-dialkyl-3-(E)-alkenyl N-tosylhydrazones using Pd-catalyzed cross-coupling conditions, which enable the Z-selective synthesis of 3-aryl-1,4-dienes and gem-dialkyl vinylcyclopropanes. We found that the dialky
Temperature-Dependent Alkylation of γ-Phenyl β,γ-Unsaturated Acid and Ester Systems in Hexamethylphosphortriamide-Tetrahydrofuran Solutions Using Lithium Diisopropylamide
Veen, Reinout H. van der,Cerfontain, Hans
, p. 342 - 346 (2007/10/02)
The reactivities of some β,γ-unsaturated carboxylic acids and their methyl esters toward alkylation with methyl iodide using the lithium diisopropylamide-hexamethylphosphortriamide (LDA-HMPT) systems in THF have been investigated.The methylation selectivity of pent-3-enoic acid (2) and (1,2-dihydro-3-naphtyl)acetic acid (6) on using 1.0 equiv. of methyl iodide is high, the α-mono- to α,α-dimethylation ratios at -78 deg C being >20.The selectivity is substantially lower for styrylacetic acid (4) and increases with increasing temperature from 2.3 at -78 deg C to 8.5 at -10 deg C.The occurrence of dimethylation is ascribed to intermolecular proton exchange between the monomethylated species IIa and the nonmethylated species Ia.For the β,γ-unsaturated esters the methylation selectivity is somewhat higher than that for the corresponding carboxylic acids.
