16654-89-0Relevant articles and documents
Sodium Butylated Hydroxytoluene: A Functional Group Tolerant, Eco-Friendly Base for Solvent-Free, Pd-Catalysed Amination
Semeniuchenko, Volodymyr,Braje, Wilfried M.,Organ, Michael G.
supporting information, p. 12535 - 12539 (2021/08/03)
NaBHT (sodium 2,6-di-tert-butyl-4-methylphenolate), a strong, but hindered and lipophilic base, has been effectively paired with similarly lipophilic, high-reactivity Pd-NHC (N-heterocyclic carbene) catalysts to produce an ideal combination for performing
NaBHT Generated in Situ from BHT and NaO tBu: Crystallographic Characterization and Applications in Buchwald-Hartwig Amination
Semeniuchenko, Volodymyr,Ovens, Jeffrey S.,Braje, Wilfried M.,Organ, Michael G.
supporting information, p. 3276 - 3290 (2021/10/12)
NaBHT is a valuable medium-strength base useful for many applications, particularly for Buchwald-Hartwig coupling. The structures of solvent-free NaBHT and its solvates with Et2O, THF, tBuOH, and a THF/tBuOH mixture were established using single-crystal X-ray diffraction. While [NaBHT·Et2O]2 adopts a dimeric structure and crystallizes in a monoclinic cell, [NaBHT·THF]3, [NaBHT·tBuOH]3, and [NaBHT·(THF-tBuOH)]3 prefer a trimeric structure and crystallize in cubic cells. Solvent-free [NaBHT]n is different from solvated NaBHT and from other known sodium phenolates. It is an inorganic polymer that crystallizes in an orthorhombic cell, with a NaO core spreading in the [1 0 0] direction. Agostic interactions of the tBu group hydrogens with Na, which were confirmed for all structures, may help explain the reductive properties of NaBHT. Further, interactions of BHT with tBuONa in solution and in the solid state were examined, reveraling that NaBHT does not need to be prepared from pyrophoric NaH or metallic Na every time. Instead, it can be generated efficiently in or ex situ using NaOtBu in solution or with only a stoichiometric amount of solvent to assist in bringing the reactants together. Application of this methodology was demonstrated with the efficient, solvent-free, and Pd-catalyzed C-N coupling with Pd(NHC) catalysts.
Sodium Butylated Hydroxytoluene (NaBHT) as a New and Efficient Hydride Source for Pd-Catalysed Reduction Reactions
Sharif, Sepideh,Rodriguez, Michael J.,Lu, Yu,Kopach, Michael E.,Mitchell, David,Hunter, Howard N.,Organ, Michael G.
supporting information, p. 13099 - 13103 (2019/10/28)
NaBHT (sodium butylated hydroxytoluene), a hindered and soluble base for the efficient arylation of various base-sensitive amines and (hetero)aryl halides has been found to have an unanticipated role as a hydride donor to reduce (hetero)aryl halides and allylic acetates. Mechanistic studies have uncovered that NaBHT, but not BHT, can deliver multiple hydrides through oxidation of the benzylic methyl group in NaBHT to the aldehyde. Further, performing the reduction with NaBHT-d20 has revealed that the redox-active benzylic position is not the only hydride donor site from NaBHT with one hydride in three coming, presumably, from the tert-butyl groups. The reduction works well under mild conditions and, incredibly, only consumes 20 percent of the NaBHT in the process; the remaining 80 percent can be readily recovered in pure form and reused. This, combined with the low cost of the material in ton-scale quantity, makes it practical and attractive for wider use in industry at scale.
A NOVEL, SIMPLE METHOD FOR THE PREPARATION OF HINDERED DIPHENYL ETHERS
Sammes, Peter G.,Thetford, Dean,Voyle, Martyn
, p. 3229 - 3232 (2007/10/02)
The displacement of the nitro group from substituted nitrobenzenes is used for the synthesis of diphenyl ethers. 1,4-Dinitrobenzene has been converted into a variety of hindered diphenyl ethers using 2,6-disubstituted phenoxides and studies show that the mechanism of formation of the ether (5a) is radical in nature.
