Stereochemistry of some aminoboranes containing N-trimethylsilyl, -germyl, or -stannyl substituents

Synthesis and some oxidation reactions of [bis(trimethylsilyl)amino]dimethylphosphine

“…In the earlier work,6 NMR spectroscopy indicated that compound 4 is undergoing a rapid 1,3-silyl exchange, thus accounting for the observation of a single, broad resonance for all of the Me3Si protons at room temperature. In our study, this result was verified by the 13C NMR spectrum of 4 which contained only a broad singlet in the Me3Si region.…”

“…Preparation of P-Bis (trimethylsilyl) amino-P.P-dimethy 1-7V-trimethylsilylphosphinimine (4). A mixture of compound 1 (28.8 mmol) and trimethylsilyl azide (30.1 mmol) was heated (55-60 °C) with stirring for 24 h, during which time evolution of a gas was observed.…”

An Experimental and ab Initio CI Study for Charge Transfer Excited States and Their Relaxation in Pyrroloborane Derivatives

“…There are numerous experimental investigations available in the literature referring to these points. Dynamical 1 H NMR − and 13 C NMR − measurements, investigations by means of electrochemical cyclic voltammetry, 11 B and 14 N NMR , as well as X-ray studies − have been performed for several triarylboranes, pyrroloboranes, and aminoborane derivatives. Most of them indicate the existence of a structure analogous to that given in Scheme , i.e., corresponding to an almost planar pyrroloborane unit with twisted mesityl substituents. − The twist angle varies strongly and is generally assumed to be situated in the range 50°−90°.…”

“…Dynamical 1 H NMR − and 13 C NMR − measurements, investigations by means of electrochemical cyclic voltammetry, 11 B and 14 N NMR , as well as X-ray studies − have been performed for several triarylboranes, pyrroloboranes, and aminoborane derivatives. Most of them indicate the existence of a structure analogous to that given in Scheme , i.e., corresponding to an almost planar pyrroloborane unit with twisted mesityl substituents. − The twist angle varies strongly and is generally assumed to be situated in the range 50°−90°. This twisted geometry should prevent a strong coupling between the locally excited states of the mesityl groups and the charge transfer state, the energy level of which is considered to be very close lying.…”

Stability and stereochemistry of some amino(bis(trimethylsilyl)amino)boranes

“…While our NMR data do not preclude the possibility that compounds 4-6 may adopt similar configurations, their chemical and thermal stability seems most consistent with the "twisted" structure that we have proposed here and elsewhere. 19 Registry No. 1, 32882-72-7; 2, 6591-24-8; 3, 6663-30-5; 4, 66322-82-5; 5, 66322-81-4; 6, 66322-80-3.…”