+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Dynamic Behavior of N-Heterocyclic Carbene Boranes: Boron-Carbene Bonds in B,B-Disubstituted N,N-Dimethylimidazol-2-ylidene Boranes Have Substantial Rotation Barriers



Dynamic Behavior of N-Heterocyclic Carbene Boranes: Boron-Carbene Bonds in B,B-Disubstituted N,N-Dimethylimidazol-2-ylidene Boranes Have Substantial Rotation Barriers



Journal of Organic Chemistry 80(9): 4465-4469



Dynamic NMR spectroscopy has been used to measure rotation barriers in five B,B-disubstituted 1,3-dimethylimidazol-2-ylidene boranes. The barriers are attributed to the sp(2)-sp(3) bond between C(1) of the N-heterocyclic carbene ring and the boron atom. Bonds to boron atoms bearing a thexyl (1,1,2-trimethylpropyl) group show especially high barriers, ranging from 75-86 kJ mol(-1). 2-Isopropyl-1,3,5-trimethylbenzene is used as a comparable to help understand the nature and magnitude of the barriers.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 057669223

Download citation: RISBibTeXText

PMID: 25843519

DOI: 10.1021/acs.joc.5b00324


Related references

Substitution reactions at tetracoordinate boron: synthesis of N-heterocyclic carbene boranes with boron-heteroatom bonds. Journal of the American Chemical Society 132(42): 15072-15080, 2010

Insertion of reactive rhodium carbenes into boron-hydrogen bonds of stable N-heterocyclic carbene boranes. Journal of the American Chemical Society 135(32): 12076-12081, 2013

Reactions of N-Heterocyclic Carbene Boranes with 5-Diazo-2,2-dimethyl-1,3-dioxane-4,6-dione: Synthesis of Mono- and Bis-hydrazonyl NHC-Boranes. Journal of Organic Chemistry 83(15): 8775-8779, 2018

Radical Reactions of N-Heterocyclic Carbene Boranes with Organic Nitriles: Cyanation of NHC-Boranes and Reductive Decyanation of Malononitriles. Journal of the American Chemical Society 137(26): 8617-8622, 2015

N-Heterocyclic Carbene Boryl Iodides Catalyze Insertion Reactions of N-Heterocyclic Carbene Boranes and Diazoesters. Organic Letters 19(13): 3680-3683, 2017

Electron paramagnetic resonance and computational studies of radicals derived from boron-substituted N-heterocyclic carbene boranes. Journal of the American Chemical Society 133(26): 10312-10321, 2011

Hydroboration of arynes with N-heterocyclic carbene boranes. Angewandte Chemie 53(48): 13150-4, 2014

Synthesis and reactions of N-heterocyclic carbene boranes. Angewandte Chemie 50(44): 10294-10317, 2011

N-Heterocyclic carbene boranes are good hydride donors. Organic Letters 14(1): 82-85, 2012

Ionic and organometallic reductions with N-heterocyclic carbene boranes. Chemistry 15(47): 12937-12940, 2009

Radical trans-Hydroboration of Alkynes with N-Heterocyclic Carbene Boranes. Angewandte Chemie 57(30): 9485-9490, 2018

Borenium ion catalyzed hydroboration of alkenes with N-heterocyclic carbene-boranes. Journal of the American Chemical Society 134(29): 12281-8, 2012

Metal-free dehydrogenation of amine-boranes by an N-heterocyclic carbene. Dalton Transactions 42(13): 4625-4632, 2013

Diastereoselective Radical Hydrogen Transfer Reactions using N-Heterocyclic Carbene Boranes. Journal of Organic Chemistry 81(22): 11427-11431, 2016

Silica gel promotes reductions of aldehydes and ketones by N-heterocyclic carbene boranes. Organic Letters 14(17): 4540-4543, 2012