Dialkylboryl-substituierte Triphenylphosphoniumylide

Abstract

Umylidierungen von mit R 22BCl im Molverhältnis 2 : 1 ergaben die neuartigen kristallinen Ylide 1, die man auch durch eine mesomere Grenzform 1b mit BC‐Bindung beschreiben kann. Bisher wurde nur mit Halogeniden von Elementen der 4.–7. Hauptgruppe umylidiert.

α‐Borylated Phosphorus Ylides (α‐BCPs): Electronic Frustration within a C−B π‐Bond Arising from the Competition for a Lone Pair of Electrons

“…To our benefit, Bestmann et al. synthesized the first α‐boryl‐substituted phosphorus ylide already in 1984, hence the synthetic access was facilitated. The drawback of this method is the employment of one equivalent of phosphorus ylide for dehydrohalogenation of the ylide–boron adduct Ph 3 PCH(CH 3 )BEt 2 Br.…”

“Push‐Pull” Substituted Allenes

“…If the non-enohzing ketones 6 are reacted with the A Do phospha-alleneylides 7 [5] at low temperature in diethyl Electron-rich allenes, such as tetrakis(dimethylamino )allene, and their electron-deficient counterparts, such as the tetraethyl-ester of allene tetracarboxylic acid, react with electrophiles and nucleophiles, respectively, at the central carbon atom (C-2) [I] .Ambiphilic carbenes such as chloro(methoxycarbene) show electrophilic and nucleophilic selectivity with electron-rich and electron-deficient olefins, respectively [2] . If, however, the donor substituent (Do) in an electrophilic carbene, 1, is replaced by a stabilized anion, and the acceptor substituent (A) by a stabilized cation, a dipolar carbene, 2, which can also be regarded as an allene 3, is obtained.…”

Synthesis of new organophosphorus‐substituted mono‐ and bis(trimethylsilyl)amines with PCH2N fragments and their derivatives

“…All reactions were carried out under dry argon in anhydrous solvents. The starting trimethylsilyl esters of trivalent organophosphorus acids and aminomethylating reagents were prepared as described in [4,5,11].…”

“…In this work, we propose the convenient way for synthesis of new organophosphorussubstituted N-trimethylsilylamines and their derivatives such as organophosphorus-substituted amides and sulfonamides of various structures. Starting trimethylsilyl esters of trivalent organophosphorus acids [1], symmetrical trialkylhexahydrotriazines [4], and N-alkoxymethyl bis(trimethylsilyl)amines [5][6][7] were used by us.…”