Varied Reactivity of the Germene Mes₂GeCR₂ toward Nitriles

Abstract

The germene Mes 2 GedCR 2 (1, CR 2 ) fluorenylidene) shows varied behavior toward nitriles. It reacts as a 1,2-dipole with t-BuCN giving a four-membered ring heterocycle, 2-aza-3germacyclobut-1-ene, as a 1,4-dipole with PhCN, leading to a six-membered ring heterocycle, 3,4-dihydro-3-germaisoquinoline, and as a base, abstracting the R-H of R′CH 2 CN to give R-cyanogermanes (R′ ) H, 2-thienyl, 2-FC 6 H 4 , 4-FC 6 H 4 ).

Versatile Reactivity of Stannene Tip2Sn═CR2 with Unsaturated Compounds

“…In mass spectroscopy, the molecular peak could not be observed: the four-membered ring decomposes to give again the starting stannene. Similar reactions between the germene Mes 2 GeCR′ 2 and acetonitrile or pivalonitrile have been reported …”

Some addition reactions of bisgermavinylidene

“…The protondecoupled 31 P NMR spectrum displayed two doublets at δ 21.89-22.01 (J p−p = 36 Hz) and δ 32.46-32.58 ppm (J p−p = 36 Hz), consistent with the solid-state structure. The 13 C NMR spectrum is normal.…”

“…They were characterized by NMR spectroscopy and X-ray structure analysis. The 1 H and 13 C NMR spectra of 2 displayed one set of resonances for the bis(iminophosphorano)methanediide ligand and adamanyl group. The 31 P NMR spectrum of 2 showed one sharp singlet at δ 25.08 ppm which is not consistent with the X-ray structure.…”

“…16 AdNCO and Ph 3 SiOH were purchased from Aldrich Chemicals and used without further purification. The 1 H (300.13 MHz), 13 C (75.47 MHz) and 31 P (121.49 MHz) spectra were recorded on Brüker WM-300 spectrometer. The NMR spectra were recorded in THF-d 8 or Benzene-d 6 and the chemical shifts δ are relative to SiMe 4 and 85% H 3 PO 4 for 1 H, 13 C and 31 P, respectively.…”

Addition of Nitriles to Two Brook Silenes

“…Given our interest in the reactivity of silenes and recent interest in the reactivity of unsaturated Group 14 compounds toward nitriles, − we have reinvestigated the addition of nitriles containing α-CH bonds to Brook silenes. Specifically, we have (re)examined the addition of CH 3 CN, CH 3 CH 2 CN and PhCH 2 CN to two Brook silenes, (Me 3 Si) 2 SiC(OSiMe 3 )R, where R = 1-Ad ( 8 ) and R = t -Bu ( 12 ), in an effort to compare directly the reactivity of naturally polarized and reduced polarity silenes toward saturated nitriles containing an α-hydrogen.…”