7492-65-1Relevant academic research and scientific papers
Bis azide-triphenylphosphine as a reagent for esterification at room temperature
Dinesh, Murugan,Archana, Sivasubramaniyan,Ranganathan, Raja,Sathishkumar, Murugan,Ponnuswamy, Alagusundaram
supporting information, p. 6975 - 6979 (2015/11/27)
Modified Staudinger reaction is a well-established reaction for the amide synthesis from organic azides and carboxylic acids in the presence of phosphorous reagents. In contrary to this, it is notable that bis azide in the presence of triethylphosphite or trimethylphosphite does not afford the expected bis amides but affords the ethyl or methyl esters of the carboxylic acids respectively. This serendipitous observation when further investigated results in the discovery of bis azide-triphenylphosphine as an efficient reagent for esterification at room temperature.
An examination of the scope and stereochemistry of the Ireland-Claisen rearrangement of boron ketene acetals
Seizert, Curtis A.,Ferreira, Eric M.
supporting information, p. 4460 - 4468 (2014/05/06)
The Ireland-Claisen rearrangement of boron ketene acetals is described. The boron ketene acetal intermediates are formed through a soft enolization that obviates the use of strong bases and the intermediacy of alkali metal enolates. Yields and diastereoselectivities of these rearrangements are very sensitive to the choice of boron reagent, even among those that have been shown to effect quantitative formation of boron ketene acetals from esters. The rearrangement occurs at room temperature for all substrates with generally high levels of stereoselectivity. In contrast to previous reports using boron triflates, the use of a commercially available boron iodide reagent allows for a wider substrate scope that extends to propionates and arylacetates, as well as the previously described α-oxygenated esters. This work also provides insight into the dynamic nature of boron ketene acetals and the ramifications of this behavior for reactions in which they are intermediates. Borane down: Boron enolates of allylic esters are efficiently generated at -78 °C using cHx2BI (dicyclohexyliodoborane)·Et3N. These rearrange smoothly on being warmed to room temperature to give generally high diastereoselectivity in forming γ,δ-unsaturated acids (see scheme). The rearrangements provide a key insight into the dynamic nature of boron ketene acetals.
A fast and simple method for the acylation of alcohols with acid chlorides promoted by metallic samarium
Jia, Xue-Shun,Wang, Hai-Long,Huang, Qing,Kong, Ling-Long,Zhang, Wei-He
, p. 135 - 138 (2007/10/03)
Acylation of primary, secondary, allyl and benzyl alcohols with acid chlorides promoted by samarium metal under neutral condition gave carboxylic acid esters in good to excellent yields. Acylation of a tertiary alcohol did not occur under the same reaction conditions.
