ONE'POT REACTION OF TRIVALENTPHOSPHORUS COMPOUNDS (I)——A NOVEL ONE-STEP REACTION OF ADDITION,REDUCTION AND CYCLIZATION OF SUBSTITUTED β-NITROSTYRENE WITH O,O-DIALKYL PHOSPHITES

Abstract

In this paper the reaction of substituted β-nitrostyrene with O,O-dialkyl phosphite under cocatalysis of trimethylsilyl chloride (TMS-C1) and triethylamine (or other acidbinding agent) has been first studied and the new cyclization reaction leading to the formation of product Ⅱ, as a new class of derivatives of 1-hydroxyindoles, difficultly accessible or inaccessible with usual methods has been observed. In the related reaction it is surprising that when the Arbuzov rearrangement occurs under mild conditions, the addition, reduction and cyclization as a one-pot reaction take place simultaneously with the formation of products Ⅰ, Ⅱ, Ⅲ. By controlling the reaction conditions the products were formed almost in specificity, and thus the most interesting cyclic products Ⅱ_(a-h) containing phosphorus-carbon bond were obtained. Their structures were confirmed by elemental analysis, IR, ~1H or ~(31)p NMR and MS spectra. The crystal structure of representative compound Ⅱ_h was determined by X-ray diffraction. The influence of molar ratio of reactants, solvents, substituents on benzene ring, acid-binding agents, time and temperature of reaction on the distribution of products Ⅰ, Ⅱ, Ⅲ was quantitatively investigated by the ~(31)P NMR method. The bioactivity remained to be tested.