28129-15-9Relevant articles and documents
Fast Addition of s-Block Organometallic Reagents to CO2-Derived Cyclic Carbonates at Room Temperature, Under Air, and in 2-Methyltetrahydrofuran
Elorriaga, David,de la Cruz-Martínez, Felipe,Rodríguez-álvarez, María Jesús,Lara-Sánchez, Agustín,Castro-Osma, José Antonio,García-álvarez, Joaquín
, p. 2084 - 2092 (2021/04/02)
Fast addition of highly polar organometallic reagents (RMgX/RLi) to cyclic carbonates (derived from CO2 as a sustainable C1 synthon) has been studied in 2-methyltetrahydrofuran as a green reaction medium or in the absence of external volatile organic solvents, at room temperature, and in the presence of air/moisture. These reaction conditions are generally forbidden with these highly reactive main-group organometallic compounds. The correct stoichiometry and nature of the polar organometallic alkylating or arylating reagent allows straightforward synthesis of: highly substituted tertiary alcohols, β-hydroxy esters, or symmetric ketones, working always under air and at room temperature. Finally, an unprecedented one-pot/two-step hybrid protocol is developed through combination of an Al-catalyzed cycloaddition of CO2 and propylene oxide with the concomitant fast addition of RLi reagents to the in situ and transiently formed cyclic carbonate, thus allowing indirect conversion of CO2 into the desired highly substituted tertiary alcohols without need for isolation or purification of any reaction intermediates.
Amberlyst-15 catalysed oxidative esterification of aldehydes using a H2O2 trapped oxidant as a terminal oxidant
Gayakwad, Eknath M.,Patil, Vilas V.,Shankarling, Ganapati S.
, p. 2695 - 2701 (2017/04/03)
A simple and efficient method has been developed for the selective oxidative esterification of aldehydes using commercially available Amberlyst-15 as a catalyst. H2O2 released from a clathrate structured 4Na2SO4·2H2O2·NaCl oxidant serves as an efficient source of terminal oxidants. Various aromatic, heteroaromatic, and aliphatic aldehydes undergo selective esterification to give good to excellent yield. The heterogeneous catalyst, Amberlyst-15, exhibits high reactivity and can be recycled over several runs. The 4Na2SO4·2H2O2·NaCl oxidant was found to be superior to commonly used oxidizing agents providing an anhydrous, easy to handle and stable form of H2O2
Efficient and simple approaches towards direct oxidative esterification of alcohols
Ray, Ritwika,Jana, Rahul Dev,Bhadra, Mayukh,Maiti, Debabrata,Lahiri, Goutam Kumar
supporting information, p. 15618 - 15624 (2016/02/18)
The present article describes novel oxidative protocols for direct esterification of alcohols. The protocols involve successful demonstrations of both "cross" and "self" esterification of a wide variety of alcohols. The cross-esterification proceeds under a simple transition-metal-free condition, containing catalytic amounts of TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy)/TBAB (tetra-n-butylammonium bromide) in combination with oxone (potassium peroxo monosulfate) as the oxidant, whereas the self-esterification is achieved through simple induction of Fe(OAc)2/dipic (dipic=2,6-pyridinedicarboxylic acid) as the active catalyst under an identical oxidizing environment. One-pot oxidative esterification: A wide variety of alcohols undergo transition-metal-free (in the presence of oxone/2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)/tetra-n-butylammonium bromide (TBAB)) selective "cross" esterification in moderate to excellent yields (see Figure). The "self" esterification process has however been achieved in the presence of Fe(OAc)2/2,6-pyridinedicarboxylic acid (dipic) as the active catalytic species under a similar oxidizing environment.