Cu-Catalyzed alkylation–cyanation type difunctionalization of styrenes with aliphatic aldehydes and TMSCN via decarbonylation

A copper-catalyzed decarbonylative alkylation–cyanation of styrene derivatives with aliphatic aldehydes and trimethylsilyl cyanide to provide chain elongated nitriles is reported. Using TBHP as oxidant and free radical initiator, the reaction...

Iron-Catalyzed decarboxylative and oxidative decarbonylative cross-coupling: A new strategy for the synthesis of monofluoroalkenes

Herein, an iron(II)-catalyzed decarboxylative and oxidative decarbonylative cross-coupling of α-fluoroacrylic acids with aliphatic aldehydes is presented. This methodology provided a novel and practical strategy for the construction of the monofluoroalkenes...

Nickel-Catalyzed Defluorinative Coupling of Aliphatic Aldehydes with Trifluoromethyl Styrenes

A simple procedure is reported for the nickel-catalyzed defluorinative alkylation of unactivated aliphatic aldehydes. The process involves the catalytic reductive union of trifluoromethyl styrenes with aldehydes using a nickel complex of a 6,6’-disubstituted bipyridine ligand with zinc metal as the terminal reductant. The protocol is distinguished by its broad substrate scope, mild conditions, and simple catalytic setup. Reaction outcomes are consistent with the intermediacy of an alpha-silyloxy(alkyl)nickel intermediate generated by a low-valent nickel catalyst, silyl electrophile, and the aldehyde substrate. Mechanistic findings with cyclopropanecarboxaldehyde provide insights into nature of the reactive intermediates and illustrate fundamental reactivity differences that are governed by subtle changes in ligand and substrate structure.

One-Pot, Catalyst-Free Synthesis of Nitriles from Aldehydes Using Aminating Reagent MsONH3OTf

An eco-friendly protocol to synthesize nitriles from their corresponding aromatic and aliphatic aldehydes in excellent yields has been developed. This is a catalyst-free protocol which employs an aminating reagent (MsONH3OTf) under mild conditions. The hydroxylamine triflic acid salts (MsONH3OTf) acted as the N source for this protocol. Our protocol proved to be easy to perform and presented good functional group tolerance.

Correlation analysis of reactivity in oxidation of some aliphatic aldehydes by 2-picolinium chlorochromate: A kinetic study

The oxidation of six aliphatic aldehydes by 2- picolinium chlorochromate (PICC) in dimethyl sulfoxide (DMSO) leads to the formation of corresponding carboxylic acids. The reaction is of first order each in PICC. A Michaelis-Menten type of kinetics is observed with respect to the aldehydes. The reaction is catalysed by hydrogen ions. The hydrogen-ion dependence has the form: kobs = a + b[H+]. The oxidation of deuteriated acetaldehyde MeCDO exhibited a substantial primary kinetic isotope effect (kH/kD = 5.69 at 298 K). The oxidation of acetaldehyde has been studied in nineteen different organic solvents. The solvent effect has been analysed using Taft's and Swain's multiparametric equations. The rate constants correlate well with Taft’s * values, reaction constants being negative. A mechanism involving transfer of hydride ion has been suggested.

Nickel-Catalyzed Decarboxylative Coupling of Redox-Active Esters with Aliphatic Aldehydes

The addition of alkyl fragments to aliphatic aldehydes is a highly desirable transformation for fragment couplings, yet existing methods come with operational challenges related to the basicity and instability of the nucleophilic reagents commonly employed. We report herein that nickel catalysis using a readily available bioxazoline (BiOx) ligand can catalyze the reductive coupling of redox-active esters with aliphatic aldehydes using zinc metal as the reducing agent to deliver silyl-protected secondary alcohols. This protocol is operationally simple, proceeds under mild conditions, and tolerates a variety of functional groups. Initial mechanistic studies suggest a radical chain pathway. Additionally, alkyl tosylates and epoxides are suitable alkyl precursors to this transformation providing a versatile suite of catalytic reactions for the functionalization of aliphatic aldehydes.