Cyanohydrins as substrates in benzoin condensation.
作者:Maria D. Rozwadowska
DOI:10.1016/s0040-4020(01)96667-0
日期:1985.1
substrates in the benzoin condensation. They were treated with aromatio aldehydes under phase-transfer conditions to result in benzoin benzoates. By this method aldehydes which fail to undergo condensation using traditional conditions could be converted into benzoins. By the Umpolung of reactivity of the pertinent aldehyde it was possible to prepare both isomeric unsymmetrical benzoins, including the
Synthesis of 2,4,5-Trisubstituted Oxazoles via Pd-Catalyzed C–H Addition to Nitriles/Cyclization Sequences
作者:Di Zhang、Hao Song、Na Cheng、Wei-Wei Liao
DOI:10.1021/acs.orglett.9b00700
日期:2019.4.19
A practical and flexible intermolecular protocol for the diverse synthesis of trisubstituted oxazole derivatives via a Pd-catalyzed direct C–H addition of electronic-rich heteroarenes to O-acyl cyanohydrins bearing an α-hydrogen/cyclization sequence is described. A wide range of trisubstituted oxazoles can be prepared from readily available starting materials in good to high yields with high efficiency
A palladium‐catalyzed tandem reaction of cyanomethyl benzoates with arylboronic acids has been achieved. Substitution at the 2‐position of cyanomethyl benzoates was found to be crucial for the selective synthesis of oxazoles and isocoumarins. Cyanomethyl benzoates afforded 2,4‐diaryloxazoles as products, while 2‐benzoyl‐substituted cyanomethyl benzoates delivered 3‐benzoyl‐4‐aryl‐isocoumarins selectively
readily available simple arenes and functionalized aliphatic nitriles. This transformation involves palladium-catalyzed C–H activation, carbopalladation and a tandem annulation sequence in one pot. Notably, the reaction proceeds efficiently under redox-neutral conditions, and exhibits high atom-economy. Deuterium-labeling experiments suggested that C–H bond cleavage of the simple arenes might be the rate-determining
Cyanobenzoylation and Hydrocyanation of Aldehydes with Benzoyl Cyanide Using No Catalyst
作者:Tsutomu Watahiki、Sayoko Ohba、Takeshi Oriyama
DOI:10.1021/ol0348295
日期:2003.7.1
[reaction: see text] In the presence of MS 4A in DMSO, cyanobenzoylation of various aldehydes with benzoylcyanide proceeded very smoothly to give the corresponding cyanohydrin benzoates in high to excellent yields without an acid or a base. On the other hand, reaction of aldehydes with BzCN in DMSO-H(2)O also occurred readily to afford the corresponding free cyanohydrins exclusively.