While numerous organo(metallic)catalyst systems were documented for dearomative hydroboration of N‐aromatics, alkoxide base catalysts have not been disclosed thus far. Described herein is the first example of alkoxide‐catalyzed hydroboration of N‐heteroaromatics including pyridines, providing a broad range of reduced N‐heterocycles with high efficiency and selectivity. Mechanistic studies revealed
Regioselective 1,4-hydroboration of pyridines catalyzed by an acid-initiated boronium cation
作者:Evan N. Keyzer、Sky S. Kang、Schirin Hanf、Dominic S. Wright
DOI:10.1039/c7cc04988a
日期:——
The reaction of the commercially available ammonium salt NH4BPh4 with a pyridine-activated pinacolborane species generates a boronium cation that facilitates the 1,4-selective hydroboration of pyridines in polar solvents. This catalytic reaction is amenable to a host of reactive functional groups and provides access to sterically bulky hydroboration products, previously inaccessible by metal-free routes
Trivalent Zirconium and Hafnium Metal–Organic Frameworks for Catalytic 1,4-Dearomative Additions of Pyridines and Quinolines
作者:Pengfei Ji、Xuanyu Feng、Samuel S. Veroneau、Yang Song、Wenbin Lin
DOI:10.1021/jacs.7b09093
日期:2017.11.8
We report the quantitative conversion of [MIV6(μ3-O)4(μ3-OH)4Cl12]6- nodes in the MCl2-BTC metal-organic framework into the [MIII6(μ3-O)4(μ3-ONa)4H6]6- nodes in MIIIH-BTC (M = Zr, Hf; BTC is 1,3,5-benzenetricarboxylate) via bimetallic reductive elimination of H2 from putative [MIV6(μ3-O)4(μ3-OH)4H12]6- nodes. The coordinatively unsaturated MIIIH centers in MIIIH-BTC are highly active and selective
Metal-Free Regio- and Chemoselective Hydroboration of Pyridines Catalyzed by 1,3,2-Diazaphosphenium Triflate
作者:Bin Rao、Che Chang Chong、Rei Kinjo
DOI:10.1021/jacs.7b09754
日期:2018.1.17
(NHP-OTf) 1 serve as efficient catalysts for the regio- and chemoselective hydroboration of pyridines under ambient condition with good functional group tolerance. Mechanistic studies indicate that a boronium salt, [(Py)2·Bpin]OTf 4, is generated concomitant with NHP-H 5 via hydride abstraction from HBpin by 1 in the initial reaction step. Hydride reduction of the activated pyridine in [(Py)2·Bpin]OTf
A robust Zintl cluster for the catalytic reduction of pyridines, imines and nitriles
作者:Bono van IJzendoorn、Jessica B. M. Whittingham、George F. S. Whitehead、Nikolas Kaltsoyannis、Meera Mehta
DOI:10.1039/d3dt02896h
日期:——
underexplored. Here, the boron functionalized [P7] cluster [(BBN)P7]2− ([1]2−; BBN = 9-borabicyclo[3.3.1]nonane) is applied in the dearomatized reduction of pyridines, as well as the hydroboration of imines and nitriles. These transformations afford amine products, which are important precursors to pharmaceuticals, agrochemicals, and polymers. Catalyst [1]2− has high stability in these reductions: recycling