由曼尼希(Mannich)制备具有相对电子富集的酚的新的空间受限的三脚架胺三(芳氧基)配体N(CH 2 C 6 H 2 -3- t Bu-5-X-2-OH)3(t Bu,X LH 3)缩合(X = OCH 3)或通过苄基保护的溴水杨醛上的还原胺化/ Hartwig-Buchwald胺化序列(X = N [C 6 H 4 - p -OCH 3 ] 2),然后使用Pearlman's催化剂(Pd (OH)2 / C)。缺乏的类似dianisylamino取代的化合物叔酚(H,An 2 N LH 3)邻位的丁基也很容易制备。所述配体被叔丁醇钛(IV)金属化以形成五配位醇盐LTi(O t Bu)。用盐酸水溶液处理叔丁醇盐可得到五配位的氯化物LTiCl,而用乙酰丙酮则可得到六配位的二酮酸酯LTi(acac)。二酮酸酯配合物t Bu,X LTi(acac)显示出可逆的基于配体的氧化,其中X = t Bu,MeO和An
由曼尼希(Mannich)制备具有相对电子富集的酚的新的空间受限的三脚架胺三(芳氧基)配体N(CH 2 C 6 H 2 -3- t Bu-5-X-2-OH)3(t Bu,X LH 3)缩合(X = OCH 3)或通过苄基保护的溴水杨醛上的还原胺化/ Hartwig-Buchwald胺化序列(X = N [C 6 H 4 - p -OCH 3 ] 2),然后使用Pearlman's催化剂(Pd (OH)2 / C)。缺乏的类似dianisylamino取代的化合物叔酚(H,An 2 N LH 3)邻位的丁基也很容易制备。所述配体被叔丁醇钛(IV)金属化以形成五配位醇盐LTi(O t Bu)。用盐酸水溶液处理叔丁醇盐可得到五配位的氯化物LTiCl,而用乙酰丙酮则可得到六配位的二酮酸酯LTi(acac)。二酮酸酯配合物t Bu,X LTi(acac)显示出可逆的基于配体的氧化,其中X = t Bu,MeO和An
aerobic oxidative C−C bond cleavage of vicinal diols catalyzed by vanadium amino triphenolates is described. Our results show that C−C bond cleavage can be performed in different solvents, under an air or oxygenatmosphere, with a large variety of glycols (cyclic or linear, with aromatic or aliphatic substituents) affording the corresponding carbonyl derivatives with high chemoselectivity. Reactions can
描述了钒氨基三酚盐催化邻位二醇的好氧氧化CC键裂解。我们的结果表明,在空气或氧气气氛下,可以使用多种乙二醇(环状或直链,具有芳族或脂肪族取代基)在不同溶剂中进行C-C键裂解,从而提供具有高化学选择性的相应羰基衍生物。可以在低至10 ppm的催化剂下达到TON达到81,000和TOF达到4150 h -1的情况下进行反应。还提出了通过密度泛函理论计算合理化的反应机理。
Titanium‐catalyzed esterification reactions: beyond Lewis acidity
作者:Lukas A. Wolzak、Jarl Ivar Vlugt、Keimpe J. Berg、Joost N. H. Reek、Moniek Tromp、Ties J. Korstanje
DOI:10.1002/cctc.202000931
日期:2020.10.20
Esterification is a key reaction and is used in many synthetic and industrial processes, yet the detailed mechanism of operation of often‐used (Lewis acid) catalysts is unknown and subject of little research. Here, we report on mechanistic studies of a titanium aminotriphenolate catalyst, using stoichiometric and catalytic reactions combined with kinetic data and density functional theory (DFT) calculations
Redox-Active Tripodal Aminetris(aryloxide) Complexes of Titanium(IV)
作者:Davide Lionetti、Andrew J. Medvecz、Vesela Ugrinova、Mauricio Quiroz-Guzman、Bruce C. Noll、Seth N. Brown
DOI:10.1021/ic100347h
日期:2010.5.17
dianisylamino-substituted compound lacking the tert-butyl group ortho to the phenol (H,An2NLH3) is also readily prepared. The ligands are metalated by titanium(IV) tert-butoxide to form the five-coordinate alkoxides LTi(OtBu). Treatment of the tert-butoxides with aqueous HCl yields the five-coordinate chlorides LTiCl, and with acetylacetone gives the six-coordinate diketonates LTi(acac). The diketonate
由曼尼希(Mannich)制备具有相对电子富集的酚的新的空间受限的三脚架胺三(芳氧基)配体N(CH 2 C 6 H 2 -3- t Bu-5-X-2-OH)3(t Bu,X LH 3)缩合(X = OCH 3)或通过苄基保护的溴水杨醛上的还原胺化/ Hartwig-Buchwald胺化序列(X = N [C 6 H 4 - p -OCH 3 ] 2),然后使用Pearlman's催化剂(Pd (OH)2 / C)。缺乏的类似dianisylamino取代的化合物叔酚(H,An 2 N LH 3)邻位的丁基也很容易制备。所述配体被叔丁醇钛(IV)金属化以形成五配位醇盐LTi(O t Bu)。用盐酸水溶液处理叔丁醇盐可得到五配位的氯化物LTiCl,而用乙酰丙酮则可得到六配位的二酮酸酯LTi(acac)。二酮酸酯配合物t Bu,X LTi(acac)显示出可逆的基于配体的氧化,其中X = t Bu,MeO和An