N–H deprotonation of a diaminodialkoxido diborane(4) – a structural study on bifunctional Lewis acids/bases and their dimerisation to B(sp2)2B(sp3)2N2 six membered rings

2021 ◽  
Vol 50 (37) ◽  
pp. 13149-13157
Author(s):  
Wiebke Drescher ◽  
Christian Kleeberg
Keyword(s):  
Structural Study ◽  
Lewis Acids

The N–H deprotonation of the diaminodialkoxido diborane(4) pinB–Bdab (1) (pin: (OCMe2)2, dab: 1,2-(NH)2C6H4), is crucial for the electrophilic N-functionalisation towards unsymmetrical diborane(4) reagents.

Etude par resonance magnétique multinucléaire d'intermédiaires réactionnels électrophiles. Partie 8. Action des acides de Lewis chlorés COCl2, POCl3, (CH3)2N=CHCl+Cl− et Cl2 sur l'hexaméthylphosphotriamide (HMPT)

1980 ◽  
Vol 58 (9) ◽  
pp. 946-952 ◽  
Author(s):  
S. Poignant ◽  
J. R. Gauvreau ◽  
G. J. Martin
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Study ◽  
Lewis Acids ◽  
Mechanism Of Formation ◽  
Substitution Product ◽  
Vilsmeier Reagent ◽  
Résonance Magnétique

The structural study of the electrophilic intermediates obtained from carboxamides and chlorinated Lewis acids is extended to the phosphoric amides. The action of COCl2 and POCl3 on hexamethylphosphotriamide (HMPT) can lead to a chlorophosphonium salt (3a) the structure of which is proved by nmr spectroscopy (1H, 13C, 31P, 15N). The mechanism of formation is comparable to that of the chloroiminium chloride (Vilsmeier reagent) from the corresponding amides. The action of chlorine on HMPT does not lead to a stable salt of the same kind but essentially to the substitution product (2). A new biphosphorylated compound (6) has been identified when an excess of chlorine is reacted with HMPT.

An Ultra-Structural Study of Human Melanoma in Vivo and Vitro

1976 ◽  
Vol 34 ◽  
pp. 258-259
Author(s):  
James R. Gaylor ◽  
Fredda Schafer ◽  
Robert E. Nordquist
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Protein Aggregation ◽  
Structural Study ◽  
Human Melanoma ◽  
Protein Matrix ◽  
Early Form ◽  
Endoplasmic Reticulum Protein ◽  
Mitochondrial Origin

Several theories on the origin of the melanosome exist. These include the Golgi origin theory, in which a tyrosinase-rich protein is "packaged" by the Golgi apparatus, thus forming the early form of the melanosome. A second theory postulates a mitochondrial origin of melanosomes. Its author contends that the melanosome is a modified mitochondria which acquires melanin during its development. A third theory states that a pre-melanosome is formed in the smooth or rough endoplasmic reticulum. Protein aggregation is suggested by one author as a possible source of the melanosome. This fourth theory postulates that the melanosome originates when the protein products of several genetic loci aggregate in the cytoplasm of the melanocyte. It is this protein matrix on which the melanin is deposited. It was with these theories in mind that this project was undertaken.

Structural study of LiPO3-TeO2 glasses

1997 ◽  
Vol 222 (1-2) ◽  
pp. 131-136
Author(s):  
K Muruganandam
Keyword(s):  
Structural Study

Structural Study of TlH2PO4 and TlD2PO4 in the High Temperature Phase

1995 ◽  
Vol 5 (7) ◽  
pp. 763-769 ◽  
Author(s):  
S. Rios ◽  
W. Paulus ◽  
A. Cousson ◽  
M. Quilichini ◽  
G. Heger ◽  
...  
Keyword(s):  
High Temperature ◽  
Structural Study ◽  
High Temperature Phase ◽  
Temperature Phase
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