173035-11-5Relevant articles and documents
Organic spirocyclic initiators for the ring-expansion polymerization of β-lactones
Jeong, Wonhee,Hedrick, James L.,Waymouth, Robert M.
, p. 8414 - 8415 (2007)
We report spirocyclic imidazolidines derived from N-heterocyclic carbenes and β-lactones. These spirocycles are initiators for the zwitterionic ring-expansion polymerization of β-lactones to generate cyclic polyesters of well-defined molecular weight. The
Strong ligand accelerated catalysis by an Arduengo-type carbene in copper-catalysed conjugate addition
Fraser, Paul K.,Woodward, Simon
, p. 2747 - 2749 (2001)
The addition of stabilised carbene ligand:CNMesCH2CH2NMes (Mes=2,4,6-Me3C6H2) results in a dramatic rate increase in the Cu(OTf)2-catalysed conjugate addition of ZnEt2 to enones (OTf=triflate anion).
Copper-NHC-Mediated Semihydrogenation and Hydroboration of Alkynes: Enhanced Catalytic Activity Using Ring-Expanded Carbenes
Hall, Jonathan W.,Unson, Darcy M. L.,Brunel, Paul,Collins, Lee R.,Cybulski, Mateusz K.,Mahon, Mary F.,Whittlesey, Michael K.
, p. 3102 - 3110 (2018/09/12)
A series of two-coordinate copper tert-butoxide complexes bearing five-, six-, and seven-membered ring N-heterocyclic carbenes, prepared by protonolysis of (NHC)CuMes with tBuOH, have been used as catalytic precursors in the semihydrogenation of alkynes with silanes/tBuOH and the hydroboration of alkynes with HBPin. Both processes proceed with high regioselectivity and show enhancements with six- and seven-membered ring carbenes.
A closer look at the reactivity between N-heterocyclic carbenes and fluoroalkenes
Leclerc, Matthew C.,Da Gama, Jason G.,Gabidullin, Bulat M.,Baker, R. Tom
, p. 81 - 89 (2017/09/30)
The fundamental reactivity leading to N-heterocyclic fluoroalkene adducts is explored in detail, featuring a total of 15 N-heterocyclic carbenes (NHCs) with various electronic and steric environments. The activity of these carbenes towards tetrafluoroethylene (TFE), hexafluoropropene (HFP), trifluoroethylene (HTFE) and vinylidene fluoride (VDF) is assessed in THF and toluene. Attempts were made to correlate the observed reactivity with electronic (Tolman Electronic Parameters) and steric (% buried volume) parameters unique to each NHC, but a trend has yet to be fully determined. However, the unique steric constraints of a cyclic (alkyl)(amino)carbene (CAAC) were shown to modify the initial point of nucleophilic attack on HTFE, providing selective transformation to a different adduct than has been observed to date with all reactions involving this fluoroalkene.