Facile Photochemical Transformation of Alkyl Aryl Selenides to the Corresponding Carbonyl Compounds by Molecular Oxygen: Use of Selenides as Masked Carbonyl Groups
作者:Takeshi Hyugano、Suyou Liu、Akihiko Ouchi
DOI:10.1021/jo801730j
日期:2008.11.21
groups on the alkyl group were transformed efficiently into the corresponding carbonylcompounds, particularly primary alkyl aryl selenides in good yields, by a simple photolysis in the presence of air or oxygen. This transformation can be conducted without protection of functional groups. The yield of carbonylcompounds was much affected by the solvent viscosity, reaction temperature, concentration
carried out in the presence of opticallyactive 4,4′-disubstituted bis(oxazoline) as a ligand together with molecular sieves, enantioselective imidation occurs to giveopticallyactive N-tosylselenimides and the best result is obtained from benzyl 2-naphthyl selenide (64% yield and 36% ee). Similar treatment of allylic selenides gives the corresponding opticallyactive allylic amides (up to 71% yield
Synthesis and characterization of some α-naphthyl selenium/tellurium derivatives: X-ray crystal structure of benzyl-1-naphthyl selenide and diphenylmethyl-1-naphthyl selenide
A large number of alpha-naphthyl selenium and tellurium compounds (1-14) have been prepared through two different methods. The first method involves the alkylation of sodium 1-naphthylselenolate/tellurolate, generated in situ using hydrazine hydrate as reducing agent while the second method involves the reaction of in situ generated alpha-naphthylseleno/telluromagnesium bromide with an appropriate electrophile. The synthesized alkyl- l- naphthyl selenides/tellurides and some alpha,omega-bis( l -naphthylseleno)alkanes have been characterized with the help of elemental analysis and using various spectroscopic techniques viz., NMR (H-1, C-13, Se-77 and Te-125), IR, UV/vis spectroscopy and mass spectrometry (only in few representative cases). Interpretation of H-1, C-13 NMR spectra and assignment of individual resonances for tris(l-naphthylseleno)methane have been done with the help of [H-1-H-1] and [H-1-C-13] correlation spectroscopy (COSY). X-ray crystallographic results and molecular geometry of benzyl-1-naphthyl selenide, 2 and diphenylmethyl-1-naphthyl selenide, 3 have also been illustrated. (c) 2005 Elsevier B.V. All rights reserved.