描述了使用用XtalFluor-E原位活化的苯甲醇对芳烃进行的Friedel-Crafts苄基化。在实验上简单温和的条件下,无需过渡金属或强路易斯酸,即可制备各种1,1,1-二芳基甲烷和1,1,1-三芳基甲烷。值得注意的是,观察到的反应性表明XtalFluor-E可能诱导苄醇的C-OH键电离和S N 1反应性。
Friedel–Crafts benzylation of arenes with benzyl fluorides has been developed. The reaction produces 1,1‐diaryl alkanes in good yield under mild conditions without the need for a transition metal or a strong Lewis acid. A mechanism involving activation of the CFbond through hydrogen bonding is proposed. This mode of activation enables the selective reaction of benzylic CF bonds in the presence of other benzylic
Borane-Catalyzed C(sp<sup>3</sup>)–F Bond Arylation and Esterification Enabled by Transborylation
作者:Dominic R. Willcox、Gary S. Nichol、Stephen P. Thomas
DOI:10.1021/acscatal.1c00282
日期:2021.3.19
given the high thermodynamic barrier to C–F bond cleavage. Stoichiometric hydridoborane-mediated C–F functionalization has recently emerged, but is yet to be rendered catalytic. Herein, the borane-catalyzed coupling of alkyl fluorides with arenes (carbon–carbonbondformation) and carboxylic acids (carbon–oxygen bondformation) has been developed using transborylation reactions to achieve catalytic
鉴于氟碳键断裂的高热力学障碍,碳氟键的活化和功能化是一个重大的合成挑战。化学计量氢化硼硼烷介导的CF功能化最近出现,但尚未被催化。在本文中,已经开发出了硼烷催化的烷基氟与芳烃(形成碳-碳键)和羧酸(形成碳-氧键)的偶联反应,以实现催化转化。在各种结构上和电子分化芳烃和羧酸的使用9-硼杂双环[3.3.1]壬烷(H-达到成功的C-C和C-O耦合乙-9-BBN)作为催化剂和频哪醇硼烷(HBpin),具有宽泛的官能团耐受性。实验和计算研究表明碳-碳和碳-氧偶联反应的机理二分法。乙-F transborylation(B-F / B-H复分解)F-之间乙-9-BBN和HBpin启用碳-碳键形成的催化周转,而烷基氟化物和acyloxyboronic酯之间的直接交换(C-F / B -O复分解)被提议用于碳-氧偶联,其中H - B -9-BBN催化羧酸与HBpin的脱氢偶联。
9-Borabicyclo[3.3.l]nonane-induced Friedel–Crafts benzylation of arenes with benzyl fluorides
作者:Jing Guo、Karlee L. Bamford、Douglas W. Stephan
DOI:10.1039/c9ob00912d
日期:——
Friedel-Craftsbenzylation of arenes with benzyl fluorides using 9-borabicyclo[3.3.l]nonane (9-BBN) as a mediator has been developed. This provides a simple and cheap route to the activation of C-F bonds to synthesize 1,1-diarylmethanes in good to excellent yields (up to 98%) under mild conditions. Functional group tolerance and the mechanism are considered.
Heteroleptic Ni(II) Complexes Bearing a Bulky Yet Flexible IBiox-6 Ligand: Improved Selectivity in Cross-Electrophile Coupling of Benzyl Chlorides with Aryl Chlorides/Fluorides
作者:Zheng-Wang Shen、Die-Die Meng、Sajid Imran、Chun-Hui Yan、Hong-Mei Sun
DOI:10.1021/acs.organomet.0c00515
日期:2020.10.12
Ni(PPh3)2Br2 to give the respective heteroleptic Ni(II) complexes Ni(IBiox-6)[P(OEt)3]Br2 (1) and Ni(IBiox-6)(PPh3)Br2 (2) in yields of 60% and 71%. Their crystal structures were characterized to reveal a rare cis disposition of the IBiox-6 ligand to the phosphite ligand in 1, while 2 possessed the more common trans configuration. Both complexes catalyzed the cross-electrophile coupling of benzyl chlorides
Vessel Effect in C-F Bond Activation Prompts Revised Mechanism and Reveals an Autocatalytic Glycosylation
作者:Michael M. Nielsen、Yan Qiao、Yingxiong Wang、Christian M. Pedersen
DOI:10.1002/ejoc.201901755
日期:2020.1.9
A significant vesseleffect during acid catalyzed C–Fbondactivations has been documented and led to revisedmechanisms for both glycosylations and benzyl fluoride activation. An autocatalytic chemical glycosylation was discovered during this investigation, further signifying the significant effect of the vessel material on a given reaction.