A method is reported for the one-carbon homologation of an alcohol to the extended carboxylic acid, ester, or amide. The process involves the Mitsunobu reaction with an alkoxymalononitrile, followed by unmasking in the presence of a suitable nucleophile. The homologation and unmasking can even be performed in a one-pot process in high yield.

The spectra of the Iodine-127 nucleus could not be readily obtained since it has a spin number, I, of 5/2 and a nonspherical charge distribution. When we applied 127I NMR to organic iodides, the I− and IO4− signals of organic molecules provided a clear singlet in solutions of (CD3)2S(O) or (CD3)2NC(O)D. The spectra of 127I NMR revealed the oxidation state of iodine atoms in the organic molecule, which would not have been evident in the 1H and 13C NMR spectra. Here, we report the practical examples of the characterization of organic iodides via solution-127I NMR spectroscopy.

In this study, 8 new spirobenzopyrans were synthesized. A novel, three-step, facile route for the synthesis of 3′-allylindoline spirobenzopyrans via 3-allyl-3H-indoles was developed. The newly synthesized spirobenzopyrans were evaluated for their photochromic properties. The presence of an allyl moiety at the 3′ position did not disturb the photochromic response. The steric effects of the diallyl groups at the 3′ position affected the interconversion between colored and colorless forms. Therefore, the allyl chain in 3′-allylindoline spirobenzopyrans can be utilized to attach these compounds to a molecular matrix. Consequently, this synthetic methodology could be readily applied to the creation of new photo-switchable materials.

X-ray crystallographic analysis revealed that the palladium-catalyzed β-allylation of yohimbine proceeded in a (7S)-selective manner. The crystal structure had an indolenine unit that was generally unstable in air. A stereoselective outcome was obtained when the palladium π-allyl complex approached yohimbine from the less-hindered pro-S side. However, during reserpine allylation—because the structure of reserpine is that of a transoid-3, 15-ring junction—the palladium π-allyl complex approached from both sides: pro-S and pro-R. A computational method was developed to discuss this selectivity. Experimental details and considerations of the reaction are provided.Highlights► An indole in yohimbine was directly allylated by cat. Pd(0) into a 3H-indole. ► X-ray crystallographic analysis revealed the solid structure of (7R)-allyl yohimbine. ► Steric effects dominate stereoselective approach of the π-allyl Pd complex.