Bellini, Clement’s team published research in Chemistry – A European Journal in 22 | CAS: 140-28-3

Chemistry – A European Journal published new progress about 140-28-3. 140-28-3 belongs to catalysis-chemistry, auxiliary class Benzenes, name is N1,N2-Dibenzylethane-1,2-diamine, and the molecular formula is C16H20N2, Application In Synthesis of 140-28-3.

Bellini, Clement published the artcileSequential Barium-Catalysed N-H/H-Si Dehydrogenative Cross-Couplings: Cyclodisilazanes versus Linear Oligosilazanes, Application In Synthesis of 140-28-3, the publication is Chemistry – A European Journal (2016), 22(44), 15733-15743, database is CAplus and MEDLINE.

Starting from Ph3SiH, the barium precatalyst Ba[CH(SiMe3)2]2¡¤(THF)3 was used to produce the disilazane Ph3SiN(Bn)SiPh2NHBn (4) by sequential N-H/H-Si dehydrogenative couplings with BnNH2 and Ph2SiH2. Substrate scope was extended to other amines and hydrosilanes. This smooth protocol gives quant. yields and full chemoselectivity. Compound 4 and the intermediates Ph3SiNHBn and Ph3SiN(Bn)SiHPh2 were structurally characterized. Further attempts at chain extension by dehydrocoupling of Ph2SiH2 with 4 instead resulted in cyclization of this compound, forming the cyclodisilazane c-(Ph2Si-NBn)2 (5) which was crystallog. authenticated. The ring-closure mechanism leading to 5 upon release of C6H6 was determined by complementary exptl. and theor. (DFT) investigations. Ba[CH(SiMe3)2]2¡¤(THF)3 and 4 react to afford the reactive Ba{N(Bn)SiPh2N(Bn)SiPh3}2, which was characterized in situ by NMR spectroscopy. Next, in a stepwise process, intramol. nucleophilic attack of the metal-bound amide on the terminal silicon atom generates a five-coordinate silicate. It is followed by turnover-limiting ¦Â-C6H5 transfer to barium; this releases 5 and forms a transient [Ba]-Ph species, which undergoes aminolysis to regenerate [Ba]-N(Bn)SiPh2N(Bn)SiPh3. DFT computations reveal that the irreversible production of 5 through such a stepwise ring-closure mechanism is much more kinetically facile (¦¤G¡Ù=26.2 kcal mol-1) than an alternative ¦Ò-metathesis pathway (¦¤G¡Ù=48.2 kcal mol-1).

Chemistry – A European Journal published new progress about 140-28-3. 140-28-3 belongs to catalysis-chemistry, auxiliary class Benzenes, name is N1,N2-Dibenzylethane-1,2-diamine, and the molecular formula is C16H20N2, Application In Synthesis of 140-28-3.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia