Organophosphorus Compounds; 129. Mesitylphosphaacetylene: Synthesis and Reactivity Studies of a New Phosphaalkyne

Abstract

Mesitylphosphaacetylene (1b) has been synthesized by AlCl 3 initiated elimination of bis(trimethylsilyl) ether from the phosphaalkene 2b . This new phosphaalkyne undergoes [3+2] cycloaddition reactions with diazo compounds ( → 6a , b ), azides ( → 8a-c ), and nitrile oxides ( → 10a , b ) to yield five-membered heterocyclic products. The mesoionic reaction partners 11 and 13 react with 1b under elimination of CO 2 and COS, respectively, to furnish the 1,3-aza-and 1,3-thiaphospholes 12 and 14 . Reaction of 1b with buta-1,3-diene leads to the diphosphatricyclooctene 18 ; it has been shown that the 1-phosphacyclohexa-1,4-diene 15 (characterized by an X-ray structure analysis of its W(CO) 5 complex 17 ) is an intermediate in the multistep reaction. Moreover, 1b has been characterized by Diels-Alder reactions with the cyclobutadiene 19 and the azacyclobutadiene 21 to afford the Dewar hetarenes 20 and 22 .

Facile, Novel Methodology for the Synthesis of Spiro[pyrrolidin-3,3′-oxindoles]: Catalyzed Ring Expansion Reactions of Cyclopropanes by Aldimines

“…[3,4] In combination, these factors have driven the development of novel, versatile, and efficient methods aimed at the synthesis of the spiro[pyrrolidin-3,3'-oxindole] moiety and related structures, as exemplified recently in the elegant total synthesis of spirotryprostatin by Danishefsky et al and of aspidophytine by Corey et al [5] We have been interested in the development of a variety of methods for the stereocontrolled synthesis of alkaloids. [6] Herein we report a novel , m(Mo Ka ) 47.05 cm À1 ; of 13 638 independent reflections (2q max 538), 12 004 were observed with F o 4 s(F o ); 900 parameters, R 1 0.0361, wR 2 0.1069; structure solution and refinement with the programs SHELXS-86 [28a] and SHELXL-93.…”

A study of the reactivity of a tetraphosphadeltacyclene*

“…The solvents were dried by standard procedures, distilled, and stored under argon. Compounds 1a-d [16], 1e [8], 2a,b, 4a, 13a [6], and 9 [17] were prepared by published methods. Column chromatography was performed in water-cooled glass tubes under argon.…”

Darstellung, Charakterisierung und Struktur funktionalisierter Fluorphosphaalkene des Typs R3E-P=C(F)NEt2 (R/E = Me/Si, Me/Ge, CF3/Ge, Me/Sn)

“…Derivatisierung des Fluorphosphaalkens Me 3 Si±P=C(F)NEt 2 (2) a) Darstellung der P-Acyl-substituierten Phosphaalkene 6±8 P-Trimethylsilylphosphaalkene erweisen sich als wertvolle Ausgangstoffe zur Synthese von weiteren Vertretern [1, 5 c, 18, 19] von Phosphaalkinen [18,20,21] sowie von phosphorhaltigen Heterocyclen mit Ringoder Ka È figstrukturen [22]. Im Zusammenhang mit der Diskussion u È ber push/pull-substituierte Phosphaalkene [5 e, 23, 24] war es fu È r uns von Interesse, aus 2 entsprechende P-Acyl-Derivate darzustellen.…”