Abstract
The stability of a variety of borane (BH3 and BH 2NHMe) and silane (SiHnPh4-n, n = 0-4) adducts with diamino (NHC) and aminoalkyl (CAAC) carbenes has been carefully examined using M06-2X/cc-pVDZ computations, including natural bond orbital and atoms-in-molecules analyses. Moreover a potential mechanism for the hydride-mediated ring expansion of the carbene donors is reported. While the NHC adducts can undergo thermally induced ring-expansion chemistry, the CAAC adducts show increased stability due to a large energetic barrier for the insertion of boron (or silicon) atoms into the CAAC heterocycle. A series of substituted NHCs were investigated to further explore the roles of both electronic and steric effects on adduct stabilities and on their propensities for undergoing ring-expansion transformations.
Original language | English (US) |
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Pages (from-to) | 6201-6208 |
Number of pages | 8 |
Journal | Organometallics |
Volume | 32 |
Issue number | 21 |
DOIs | |
State | Published - Nov 11 2013 |