Direct Room‐Temperature Lactonisation of Alcohols and Ethers onto Amides: An “Amide Strategy” for Synthesis

Abstract

Last‐minute deal: A direct lactonisation of ethers and alcohols onto amides that proceeds at room temperature under mild conditions is reported (see scheme). This allows the effective saving of up to two unproductive, sequential deprotection operations in synthetic sequences. Mechanistic studies are described, and a new “amide strategy” that exploits the dual robustness/late‐stage selective activation properties of this functional group is outlined.

α-Silyl Amides: Effective Bifunctional Lynchpins for Type I Anion Relay Chemistry

“…One such reaction comprises the direct cyclization of the γ -hydroxyamides to furnish γ -lactones (Scheme 4). 21 To this end, lynchpin 1 was combined with ( R )-(–)-benzyl glycidol ether 19 to furnish 20 in good yield with modest levels of diastereoselectivity. Following exposure to triflic anhydride, the known lactone 21 22 was isolated in 80% yield.…”

Deamination of N→Sn‐Coordinated Organotin(II) Hydroxide: Formation of a New C–O Covalent Bond

“…A new covalent C-O bond was formed in the coordination sphere of a NǞBi coordinated complex and Ir III aqua complexes during reactions with oxygen and boronic acids, respectively. [18] [17] Recently, the direct room-temperature lactonization of alcohols and ethers onto amides was also reported.…”

Oxidative activation of dihydropyridine amides to reactive acyl donors

“…In most cases these take advantage of primary amides using either high temperatures (100 to 160°C) or added metals as essential activating reagents. 19,20 Herein, we present a new activatable acyl donor which in the "off-state" is stable towards nucleophilic attack by e.g. [14][15][16][17][18] The strategy resulted in either the free acid or a new ester bond.…”