1878-68-8Relevant articles and documents
BiCl3-Facilitated removal of methoxymethyl-ether/ester derivatives and DFT study of -O-C-O- bond cleavage
Pacherille, Angela,Tuga, Beza,Hallooman, Dhanashree,Dos Reis, Isaac,Vermette, Mélodie,Issack, Bilkiss B.,Rhyman, Lydia,Ramasami, Ponnadurai,Sunasee, Rajesh
supporting information, p. 7109 - 7116 (2021/05/03)
A simple method for the cleavage of methoxymethyl (MOM)-ether and ester derivatives using bismuth trichloride (BiCl3) is described. The alkyl, alkenyl, alkynyl, benzyl and anthracene MOM ether derivatives, as well as MOM esters of both aliphatic and aromatic carboxylic acids, were deprotected in good yields. To better understand the molecular roles of BiCl3and water for MOM cleavage, two possible binding pathways were investigated using the density functional theory (DFT) method. The theoretical results indicate the differential initial binding site preferences of phenolic and alcoholic MOM substrates to the Bi atom and suggest that water plays a key role in facilitating the cleavage of the MOM group.
Pd(OH)2/C, a Practical and Efficient Catalyst for the Carboxylation of Benzylic Bromides with Carbon Monoxide
Wakuluk-Machado, Anne-Marie,Dewez, Damien F.,Baguia, Hajar,Imbratta, Miguel,Echeverria, Pierre-Georges,Evano, Gwilherm
, p. 713 - 723 (2020/02/04)
A simple, efficient, cheap, and broadly applicable system for the carboxylation of benzylic bromides with carbon monoxide and water is reported. Upon simple reaction with only 2.5 wt % of Pearlman's catalyst and 10 mol % of tetrabutylammonium bromide in tetrahydrofuran at 110 °C for 4 h, a range of benzylic bromides can be smoothly converted to the corresponding arylacetic acids in good to excellent yields after simple extraction and acid-base wash. The reaction was found to be broadly applicable, scalable, and could be successfully extended to the use of ex situ-generated carbon monoxide and applied to the synthesis of the nonsteroidal anti-inflammatory drug diclofenac.
Resolution of Vaulted Biaryl Ligands via Borate Esters of Quinine and Quinidine
Cagnon, Brian R.,Mohammadlou, Aliakbar,Wulff, William D.,Yin, Xiaopeng,Zheng, Li
, p. 10432 - 10450 (2020/09/23)
Given the sudden and unexplained rise in the cost of (+)- A nd (-)-sparteine, an alternative method for the resolution of vaulted biaryls has been developed. This method involves the reaction of a racemic vaulted biaryl ligand with one equivalent of BH3·SMe2 and one equivalent of either quinine or quinidine. A precipitate then forms from the resulting mixture of diastereomeric borates as a result of differential solubilities. Hydrolysis of the precipitate then liberates the (S)-ligand in the case of quinine and the (R)-ligand in the case of quinidine, both with >99% ee. This method has been applied to 16 different vaulted biaryl ligands, including 10 whose preparation is described here for the first time. In addition, proof of principle has been demonstrated for the dynamic thermodynamic resolution of the vaulted biaryl ligands with this method in combination with a nonchiral copper(II) complex that can racemize the ligand.