Original one-pot microwave-promoted Hunsdiecker–Suzuki strategy: straightforward access to trans-1,2-diarylethenes from cinnamic acids

Tandem Heck/Decarboxylation/Heck Strategy: Protecting‐Group‐Free Synthesis of Symmetric and Unsymmetric Hydroxylated Stilbenoids

“…Conventionally, the hydroxy stilbene 1 can be accessed through a protection/deprotection strategy11 involving Heck coupling between 4‐iodoanisole (protected halophenol) and acrylic acid with a subsequent Hunsdiecker reaction5d, 11a/Suzuki coupling,11b and a final demethylation11c with boron trihalide. Hence, the utility of our optimized HDH protocol was ascertained through synthesis of a diverse array of symmetric hydroxylated stilbenoids using acrylic acid and halophenols bearing different substitutents (Table 3, entries 1–7).…”

CO2 production in the bromate‐1,4‐cyclohexanedione oscillatory reaction

“…It may also be possible that this overall transformation of benzoquinone to 4 is accomplished via a Lieben haloform reaction, as they are known to be initiated by both silver bromate and NaOBr; [23,24] we consider this less likely due to the strongly acidic conditions in the current case. Following aldehyde oxidation of 4 to the b-keto acid function ((Z)-5), acid induced hemi-acetal formation (6), and dehydration would give (7), which has been proposed previously by our group to undergo a Hunsdiecker-type decarboxylative bromination [25][26][27][28] The most plausible mechanism for dibromoacetic acid formation also initiates with Baeyer-Villiger oxidations, but of 2,5-dibromobenzoquinone, and on both ketone carbonyls, affording eight-membered ring compound 9. Hydrolysis of the enol ester functions would then afford two molecules of brominated b-oxo carboxylic acid 10.…”

1‐(α‐Aminobenzyl)‐2‐naphthol as phosphine‐free ligand for Pd‐catalyzed Suzuki and one‐pot Wittig‐Suzuki reaction

“…One‐pot synthesis of stilbenes by dehydrohalogenation–Heck olefination and multi‐component Wittig–Heck reaction was recently accomplished by the present authors d. Cascade reactions involving Suzuki reaction as one of the steps have been reported in the literature, although almost all involve phosphine‐based catalyst systems [2e,36–50]. A few examples of double Suzuki reactions have been reported in which excellent control for two different reagents was achieved .…”