22520-37-2Relevant articles and documents
A Colorimetric Method for Quantifying Cis and Trans Alkenes Using an Indicator Displacement Assay
Valenzuela, Stephanie A.,Crory, Hannah S. N.,Yao, Chao-Yi,Howard, James R.,Saucedo, Gabriel,de Silva, A. Prasanna,Anslyn, Eric V.
supporting information, p. 13819 - 13823 (2021/05/17)
A colorimetric indicator displacement assay (IDA) amenable to high-throughput experimentation was developed to determine the percentage of cis and trans alkenes. Using 96-well plates two steps are performed: a reaction plate for dihydroxylation of the alkenes followed by an IDA screening plate consisting of an indicator and a boronic acid. The dihydroxylation generates either erythro or threo vicinal diols from cis or trans alkenes, depending upon their syn- or anti-addition mechanisms. Threo diols preferentially associate with the boronic acid due to the creation of more stable boronate esters, thus displacing the indicator to a greater extent. The generality of the protocol was demonstrated using seven sets of cis and trans alkenes. Blind mixtures of cis and trans alkenes were made, resulting in an average error of ±2 % in the percentage of cis or trans alkenes, and implementing E2 and Wittig reactions gave errors of ±3 %. Furthermore, we developed variants of the IDA for which the color may be tuned to optimize the response for the human eye.
dl-SElective pinacol-type coupling using zinc, chlorosilane, and catalytic amounts of Cp2VCl2; dl-1,2-dicyclohexylethanediol: (1,2-ethanediol,1,2-dicyclohexyl-)
Hirao, Toshikazu,Ogawa, Akiya,Asahara, Motoki,Muguruma, Yasuaki,Sakurai, Hidehiro,Krause, Helga,Fürstner, Alois
, p. 26 - 32 (2017/09/28)
-
Pinacol Coupling of Aliphatic Aldehydes Promoted by Niobium (III) Reagent
Szymoniak, Jan,Besancon, Jack,Moise, Claude
, p. 2841 - 2848 (2007/10/02)
NbCl3 (DME) was found to be a useful reagent for the intermolecular pinacol coupling of aliphatic aldehydes.The high anti diastereoselectivity of this reaction (dl / meso >/= 9 / 1) did not depend on the variation in the aldehyde alkyl chain.With respect to intramolecular pinacolization, the loss of the stereoselectivity observed is consistent with the mechanism involving an insertion of the oxo-group into the metal-carbon bond of the intermediate niobiooxirane. - Key Words: Nb(III) reagent; Pinacol coupling; Acetalization; Stereoselectivity