Formation of Nitriles, Carboxylic Acids, and Derivatives by Rearrangements

Abstract

Willgerodt and Related Reactions Baeyer–Villager Beckmann and Related Reactions Schmidt Curtius Oxaziridine→Amide Favorski and Related Reactions Benzilic Acid Arndt–Eistert and Wolff Cope Aza–Cope Claisen Aza‐Claisen and Related Rearrangements Allylic Selenides Imidate Esters 2,3‐Sigmatropic Rearrangement Ene Reaction‐Oxidation Ring Opening Ring Expansion Decarboxylation–Allylation Other Reactions

Titanium Tetrachloride-Assisted Direct Esterification of Carboxylic Acids

“…In the field of organic chemistry, the search for efficient methods for synthesizing carboxylic acid esters is an important research focus [ 1 ]. This is crucial due to the widespread presence of ester units in organic materials, pharmaceutical compounds, and natural products [ 2 , 3 ]. The synthesis of esters is mainly based on the utilization of corresponding carboxylic acids as key starting materials.…”

One‐Pot Preparation of C1‐Homologated Aliphatic Nitriles from Aldehydes through a Wittig Reaction under Metal‐Cyanide‐Free Conditions

“…or halides with metal cyanides (for C 1 homologation). [2] However, in the latter method, highly toxic metal cyanides are required (Scheme 1). Herein, as part of our studies of the use of molecular iodine in organic synthesis, [3] we report the one-pot preparation of C 1 -homologated aliphatic nitriles from aldehydes by carrying out a Wittig reaction with (methoxymethyl)triphenylphosphonium chloride and sodium hexamethyldisilazide (NaHMDS), a hydrolysis of the resulting methyl vinyl ether with pTsOH, and treating the obtained aldehyde with molecular iodine and aqueous ammonia.…”

Pd-Catalyzed Rearrangement of N-Alloc-N-allyl Ynamides via Auto-Tandem Catalysis: Evidence for Reversible C–N Activation and Pd(0)-Accelerated Ketenimine Aza-Claisen Rearrangement

“… , We envisaged that if N -alloc- N -allyl ynamides were utilized, two sequential palladium-catalyzed allylic rearrangements could occur through an N -allyl ketenimine intermediate. This approach would provide a unique method for the synthesis of quaternary nitriles bearing two independent allyl groups . More importantly, we hypothesized that both allylic rearrangements could be performed by a single palladium catalyst through two distinct mechanisms, one π-allylic and one sigmatropic.…”