Interrogating Pd(II) Anion Metathesis Using a Bifunctional Chemical Probe: A Transmetalation Switch
作者:John J. Molloy、Ciaran P. Seath、Matthew J. West、Calum McLaughlin、Neal J. Fazakerley、Alan R. Kennedy、David J. Nelson、Allan J. B. Watson
DOI:10.1021/jacs.7b11180
日期:2018.1.10
Ligand metathesis of Pd(II) complexes is mechanistically essential for cross-coupling. We present a study of halide→OH anion metathesis of (Ar)PdII complexes using vinylBPin as a bifunctional chemical probe with Pd(II)-dependent cross-coupling pathways. We identify the variables that profoundly impact this event and allow control to be leveraged. This then allows control of cross-coupling pathways
Direct Synthesis of Alkenylboronates from Alkenes and Pinacol Diboron via Copper Catalysis
作者:Wenkui Lu、Zengming Shen
DOI:10.1021/acs.orglett.8b03599
日期:2019.1.4
We report an efficient approach for the direct synthesis of alkenylboronates using copper catalysis. The Cu/TEMPO catalyst system (where TEMPO = (2,2,6,6-tetramethylpiperidin-1-yl)oxyl) exhibits both excellent reactivity and selectivity for the synthesis of alkenylboronates, starting from inexpensive and abundant alkenes and pinacol diboron. This approach allows for the direct functionalization of
CuII-catalyzed regioselective borylation of alkynes and alkenes
作者:Shiwen Liu、Xiaojun Zeng、Bo Xu
DOI:10.1016/j.tetlet.2016.06.077
日期:2016.8
We developed a regioselective borylation of alkynes and alkenes protocol based on air-stable CuII/multi-dentate ligand system. Our catalytic system gives exclusive β-borylation products for most substrates in excellent chemical yields. We propose that multi-dentate electron poor nitrogen ligands can effectively discourage the formation of α-addition product through the steric hindrance and at same
我们开发了基于空气稳定的Cu II /多齿配体系统的炔烃和烯烃方案的区域选择性硼化。我们的催化系统以优异的化学收率为大多数底物提供独家的β-硼化产物。我们提出,多齿电子贫氮配体可以通过空间位阻有效地阻止α-加成产物的形成,同时保持良好的反应性。
Aluminum Hydroxide Secondary Building Units in a Metal–Organic Framework Support Earth-Abundant Metal Catalysts for Broad-Scope Organic Transformations
作者:Xuanyu Feng、Pengfei Ji、Zhe Li、Tasha Drake、Pau Oliveres、Emily Y. Chen、Yang Song、Cheng Wang、Wenbin Lin
DOI:10.1021/acscatal.9b00259
日期:2019.4.5
suggested σ-bond metathesis as a key step for the MIL-53(Al)-CoH-catalyzed addition reactions. MIL-53(Al)-FeCl competently catalyzed oxidative Csp3–H amination and Wacker-type alkene oxidation. XANES analysis revealed the oxidation of FeII to FeIII centers in the activated MIL-53(Al)-FeCl catalyst and suggested that oxidative Csp3–H amination occurs via the formation of FeIII–OtBu species by single electron
氧化铝(Al 2 O 3)表面的固有异质性对氧化铝负载的单中心非均相催化剂的开发提出了挑战,并阻碍了在分子水平上催化物种的表征以及对催化反应机理细节的阐明。 。这里,我们报告与式Al(μ在MIL-53(Al)的金属-有机骨架(MOF)的使用氢氧化铝次级结构单元的(事业部)2 -OH)(BDC)(BDC = 1,4-苯二甲酸)作为Al 2 O 3表面的均匀且在结构上定义的功能模拟物,用于负载地球富集金属(EAM)催化剂。该μ 2MIL-53(Al)SBU中的-OH基很容易去质子化,并用CoCl 2和FeCl 2金属化,从而得到MIL-53(Al)-CoCl和MIL-53(Al)-FeCl预催化剂,其特征在于粉末X射线衍射,氮吸附,元素分析,密度泛函理论和扩展X射线精细结构光谱学。用NaBEt 3 H活化将MIL-53(Al)-CoCl转化为MIL-53(Al)-CoH,可有效催化炔烃和腈的硼
Enantioselective Conjunctive Cross-Coupling of Bis(alkenyl)borates: A General Synthesis of Chiral Allylboron Reagents
作者:Emma K. Edelstein、Sheila Namirembe、James P. Morken
DOI:10.1021/jacs.7b01774
日期:2017.4.12
conjunctive cross-coupling is used for the synthesis of enantioenriched allylboron reagents. This reaction employs nonsymmetric bis(alkenyl)borates as substrates and appears to occur by a mechanism that involves selective activation of the less substituted alkene followed by migration of the more substituted alkene during the course of a Pd-induced metalate rearrangement.