2,5-Dihydro-1,2,5-azoniastannaboratole: Nützliche Vorstufen für die Heterocyclensynthese / 2,5-Dihydro-1,2,5-azoniastannaboratole: Useful Steps for the Synthesis of Heterocycles

Abstract

<jats:title>Abstract</jats:title><jats:p> Organoboration, Heterocycles, Multinuclear NMR 1,1-Organoboration of diethylamino-dimethyl-(1-propynyl)stannane (6), formed by an exchange reaction between the bis(propynyl)-(4) and bis-(diethylamino)dimethylstannane (5), with trimethyl-(2a) or triethylborane (2b) leads to highly reactive new heterocyclic compounds (7). Both, the coordinative N→B and the weak Sn-N bond are readily attacked by H-acidic compounds. Ammonia or primary amines are used as examples. Multinuclear NMR (<jats:sup>1</jats:sup>H, <jats:sup>11</jats:sup>B, <jats:sup>13</jats:sup>C, 15 N, <jats:sup>119</jats:sup>Sn) data serve for the characterization.</jats:p>

Metallacyclopentadienes and related heterocycles via 1,1‐organoboration of alkyn‐1‐ylmetal compounds

“…Starting from alkyn-1-yltin compounds, in which the Sn C C R 1 group and an Sn X function (X = Cl or Br) are present, the 1,1-ethylboration leads to useful alkenyltin compounds of the type 18 [6,33] or 19 [34] (Scheme 8). The N Sn coordination in 19 follows from a consistent set of multinuclear NMR data [34,35] in comparison with 18 (X = Cl).…”

Novel Organo-Substituted 2,5-Dihydro-1-Azoniaand -1-Phosphonia-2-Stanna-5-Boratoles

“…As for 2 [4], the 11 B and 119 Sn NMR data are typical of the 1,5-dihydro-1-azonia-2-stanna-5-boratoles. The δ 11 Β values indicate the presence of tetra-coordinate boron atoms [12] with a strong coordinative N-B bond.…”

“…Starting materials such as 1 [3], 2 [4], P(SiMe 3 ) 3 [25], P(SnMe 3 ) 3 , Ph 2 PSnMe 3 [26], LiPPh 2 [27], PhPH 2 [28], PhAsH 2 [29], Ph 2 AsH [30] were prepared as described. Ph 2 PH was used as a commercial sample.…”

“…Thus, (E)-2-(chlorodimethylstannyl)-3-diethylboryl-pent-2-ene 1 [3] and 1,1,4,5,5-pentaethyl-2,2,3-trimethyl-1-azonia-2-stanna-5-boratole 2 [4] are readily available (Scheme 1), and the presence of numerous reactive sites is promising for further useful transformations of these compounds [5] An alternative route to 1-azonia-2-stanna-5-boratoles should be provided by the reaction of 1 with N-stannylamines. A convenient access to 1-phosphonia-2-stanna-5-boratoles should be possible either from 1, either by reaction with lithium phosphides or trimethylstannylphosphanes, or from 2 by reaction with phosphanes and liberation of diethylamine, a well established procedure for building Sn-P bonds [6], In this work, we report on such reactions and on the characterisation of the products by multinuclear magnetic resonance.…”