82199-96-0Relevant academic research and scientific papers
Access to Enantiopure Triarylmethanes and 1,1-Diarylalkanes by NHC-Catalyzed Acylative Desymmetrization
Lu, Shenci,Song, Xiaoxiao,Poh, Si Bei,Yang, Hui,Wong, Ming Wah,Zhao, Yu
supporting information, p. 2275 - 2281 (2017/02/23)
We present herein an unprecedented, efficient and enantioselective synthesis of triarylmethanes and 1,1-diarylalkanes through N-heterocyclic carbene-catalyzed acylative desymmetrization of bisphenols. This method utilizes readily available substrates, reagents and a simple procedure to deliver the valuable products in excellent enantiopurity. DFT calculations reveal that the selectivity is governed by the C?C bond cleavage step of the tetrahedral intermediate leading to the ester product. A transition state model featuring a combination of intramolecular hydrogen bond and steric effect is developed to explain the enantioselectivity.
Regiospecificity in Reactions of Metal Phenoxides. Synthesis of 2,2'-alkylidenebisphenols
Casiraghi, Giovanni,Casnati, Giuseppe,Pochini, Andrea,Ungaro, Rocco
, p. 805 - 808 (2007/10/02)
The reactions between aryloxymagnesium bromides (1) with linear aliphatic aldehydes (2) and their acetals (10) in aprotic solvents of variable donicity have been investigated.In benzene high ortho-regiospecificity is observed in all cases, although with the aldehyde (2) the yield of 2,2'-alkylidenebisphenols (5) is usually low because of the competing aldehyde self-condensation.This process is avoided using diethyl acetals as electrophilic reagents which give the products (5) in good yields.
