Selective esterifications of alcohols and phenols through carbodiimide couplingsElectronic supplementary information (ESI) available: the characterization of new compounds and literature references for known compounds. See http://www.rsc.org/suppdata/ob/b3/b312559a/
作者:Rimma Shelkov、Moshe Nahmany、Artem Melman
DOI:10.1039/b312559a
日期:——
Esterification of carboxylic acids capable of forming ketene intermediates upon treatment with carbodiimides permits the selectiveacylation of alcohols in the presence of phenols lacking strong electron-withdrawing groups. The selectivity of acylations involving highly acidic phenols could be reversed through the addition of catalytic amount of acid. Esterification of other carboxylic acids was found
Phosphonic acids having labile functional groups have been prepared quantitatively by the hydrolysis of bis(trimethylsilyl) phosphonates, were prepared by the reaction under mild conditions of the corresponding dialkyl phosphonates with bromotrimethylsilane.
A novel aerobic manganese-catalyzed oxophosphorylation reaction of carbon-carbon doublebonds of styrene derivatives and vinyl ethers using diethyl H-phosphonates was developed. This direct transformation of alkenes to β-ketophosphonate readily proceeded at room temperature via the direct incorporation of molecular oxygen present in air (open flask).
Reversal of Regioselection in the Sharpless Asymmetric Aminohydroxylation of Aryl Ester Substrates
作者:Adam J. Morgan、Craig E. Masse、James S. Panek
DOI:10.1021/ol9903032
日期:1999.12.1
[formula: see text] The asymmetric synthesis of beta-hydroxy-alpha-amino acids is reported which relies on the use of alpha,beta-unsaturated aryl ester substrates and the dihydroquinyl alkaloid ligand system (DHQ)2-AQN to control the regio- and enantioselectivity of the asymmetricaminohydroxylation (AA) process. alpha,beta-Unsaturated ester substrates of type 1 have a significant effect on the substrate-ligand