Syntheses of perdeuterated indoles and derivatives as probes for the biosyntheses of crucifer phytoalexins

Abstract

A simple two‐step preparation of [2H4]indole, a starting material necessary for the synthesis of various crucifer metabolites, starting with readily available 1H NMR solvent [2H5]nitrobenzene (99% deuterated) was developed. [4,5,6,7‐2H4]Indole 99% deuterated at the specified positions was then used to synthesize [4′,5′,6′,7′‐2H4]indolyl‐3‐acetaldoxime, [4′,5′,6′,7′‐2H4]1‐methoxyindolyl‐3‐acetaldoxime, [1″,1″,1″,4′,5′,6′,7′‐2H7]1‐methoxyindolyl‐3‐acetaldoxime, [4′,5′,6′,7′‐2H4]1‐methoxybrassinin, and [3,3,3,4′,5′,6′,7′‐2H7]1‐methoxybrassinin. Copyright © 2005 John Wiley & Sons, Ltd.

Ecological Roles of Tryptanthrin, Indirubin and N‐Formylanthranilic Acid in Isatis indigotica: Phytoalexins or Phytoanticipins?

“…Tetradeuterated indole (9a; ca. 96 % D 4 ) was synthesized as previously reported, [31] and dideuterated anthranilic acid (7a; ca. 96 % D 2 ) was prepared by proton/deuteron exchange, as described in the Supporting Information.…”

Indolyl-3-acetaldoxime dehydratase from the phytopathogenic fungus Sclerotinia sclerotiorum: Purification, characterization, and substrate specificity

“…Diisobutylaluminum hydride (1.5 M solution in toluene, 0.85 ml, 1.28 mmol) was added dropwise to a stirred solution of indolyl-3-acetonitrile (3) (100 mg, 0.64 mmol) in dry toluene (14 ml) at À78°C under Ar atmosphere (Pedras and Okinyo, 2006). The reaction mixture was stirred for 20 min at the same temperature, poured into ice cold 5% HCl (20 ml) and extracted with EtOAc.…”

“…Indolyl-3-acetaldoxime (1) was obtained from reduction of indolyl-3-acetonitrile (3) with DIBAL-H followed by oximation, as detailed in Section 4 and previously described for the tetradeuterated compound (Pedras and Okinyo, 2006). Naphthylacetaldoximes 19 and 20 were prepared from the corresponding naphthylacetonitriles 17 and 18 using DIBAL-H in toluene (Fig.…”

Mechanochemical Synthesis and Isomerization of N-Substituted Indole-3-carboxaldehyde Oximes †

“…The individual syn and anti isomers were separated by column chromatography and the possibility of mutual isomerization was shown. Later on, the same reaction was also performed by Pedras et al with quantitative yield [57].…”