Dialkylboryl‐Substituted Triphenylphosphonium Ylides

Abstract

Transylidation of R1HC⊕P⊕Ph with R 22BCl in the molar ratio 2 : 1 furnished the novel crystalline ylides 1, which can also be described in terms of a mesomeric formulation 1b with BC bonding. Hitherto, transylidations have been carried out only with halides of the 4th—7th main group elements.

Reaction of stannyl-substituted phosphorus ylides with boron trifluoride diethyl etherate: evidence for formation of transient triphenylphosphonio-substituted stannaethenes

“…The formation of 11 could be explained by a dimerization of transient stannaethene 14, while 12 stems from transylidation reactions. Further byproducts were boranyl-substituted phosphoranylmethanes 13,15 which have not been studied in detail. An X-ray diffraction analysis has been carried out for 11 and 12, and the mo- To further support the assumption that stannavinylphosphonium salt 14 is an intermediate, the reaction was repeated in the presence of benzophenone as a trapping reagent.…”

“…Thus, it is possible that cyclic intermediate 17, before it collapses to stannavinylphosphonium salt 14, is attacked by uncomplexed 4 to give 18 and finally 11 via a stepwise intermolecular reaction sequence. Likewise, the formation of stannaoxetane 20 and its subsequent decomposition to 15 might be explained by nucleophilic addition of benzophenone to 17.21…”

“…Mp: 202°C. NMR (CDC13): 1.14 (s, 18 H, tBuCHg, Ju9SnH = 100.1 Hz, J>i7SnH = 95.7 Hz), 2.56 (d, =/PH = 15.4 Hz, 2 H, CH2), 7.42-7.87 (m,15 H, aromatic H). 19F NMR (CDClg): = -150.4 (s, BF4), -191.5 (s, SnF, Jnag^= 2404 Hz, =/mSnF = 2302 Hz).…”

“…Yield: 1.72 g (81%). NMR (CDC13): -0.86 (s, 9 H, tBu CH3, e/negnH = 99.1 Hz, e/n^gnH = 95.2 Hz), 1.37 (s, 9 H, tBuCH3, JmSnH = 85.0 Hz, Jn7SnH = 82.0 Hz), 1.84 (d, e/pH = 22.7 Hz, 3 H, CH3), 7.37-8.01 (m, 15 (iv) Reaction of 5 with BF3OEt2 in the Presence of Benzophenone. The colorless solid is recrystallized from 5 mL of THF.…”

“…Mp: 191-192 °C. NMR (CDC13): = 1.17 (d, JHf = 1-5 Hz, 18 H, tBuCHg, =/n8gnH = 100.83 Hz, «/n'snH = 96.19 Hz), 6.93 [d (the geminal coupling constant JHh could not be resolved), JPH = 37.35 Hz, 1H, vinyl CH2], 6.99 [d (the geminal coupling constant JHH could not be resolved), e/PH = 35.64 Hz, 1 H, vinyl CH2], 7.63-7.90 (m, 15 H, aromatic H). 19F NMR (CDC13): = -150.4 (s, 4 F, BF4), -196.5 (s, 1 F, SnF, e/iuggp -2448 Hz, Jing^p -2338 Hz).…”