2015年7月22日 · Note that this mechanism does in fact include hydride transfers (it has to). Though you were right in thinking that $\ce{BH3}$ wouldn't immediately donate a hydride, coordinating to a lone pair weakens the $\ce{B-H}$ bonds and makes hydride transfers possible. $\ce{BH3}$ and $\ce{NaBH4}$ really aren't as different as you might first think.

2022年1月30日 · This reaction is taken from: Pintér, Á.; Sud, A.; Sureshkumar, D.; Klussmann, M. Autoxidative Carbon-Carbon Bond Formation from Carbon-Hydrogen Bonds.

2017年6月29日 · First, I understand that, on $\ce{BH3}$, they eletronegativity difference between $\ce{B}$ and $\ce{H}$ is very small. Which mean that the $\ce{B-H}$ bond is less polarized. But, I couldn't find a relation of this, to the fact that he is a Molecular hydride.

2018年8月1日 · BBr3 is more acidic than BCl3 due to weaker pi back bonding in BBr3 as compared to BCl3.BCl3 is stronger acid than BH3 due to electron withdrawing effect of Cl make B becomes more electron deficient despite of pi back bonding in BCl3. Due to steric reason BMe3 is stronger acid than BPh3.

2019年2月14日 · The reduction of secondary amides with BH3 requires 3 equivalents, mechanism shown below image sourced from here. The borane becomes HB=O which may transform further depending on work up. The borane becomes HB=O which …

$\begingroup$ hint; most important factor in BX3 is the bonding between X and B which is going to determine the acidic strength , and here we can clearly see that in BF3 there is the partial double bond character between atoms which is due to back bonding (2pi-2pi), and gradually back bonding weakens and lewis acidic character increases so your final order will be. …

2017年8月1日 · I believe methanol does protonate the alkoxide. The resulting methoxide coordinates to $\ce{BH3}$ forming $\ce{(MeO)BH3-}.$ The electron donating character of the methoxy group makes the remaining protons more hydride which results in a more reactive hydride source.

2020年1月3日 · Lewis acidity is a function of electron deficiency on the acceptor atom, which in this case is $\\ce{B}$ and $\\ce{Al}$ respectively. Back donation is better as is the case of $\\ce{B}$, due to bett...

2017年12月7日 · In the hydroboration reactions of alkenes I've seen so far, they were always followed by oxidation with $\ce{H2O2/NaOH}$ (to yield alcohols).

2012年5月4日 · $\ce{B}$ has an $2s^22p^1$ valence shell, so three covalent bonds gives it an incomplete octet. $\ce{BH3}$ has an empty $2p$ orbital. This orbital overlaps the existing $\ce{B-H}$ $\sigma$ bond cloud (in a nearby $\ce{BH3}$), and forms a 3c2e bond. It seems that there are a lot more compounds with 3c2e geometry. I'd completely forgotten that ...