描述了旨在探测黄素促进的胺氧化脱氨基的研究。已发现 3-甲基发光黄素 (3MLF) 在酸(HCl 或 MgCl 2 )催化的热(80 o C)条件下促进苄胺向 N-苄基苯扎二亚胺的清洁转化。该反应受多重周转的影响。发现胺结构 (1 o >2 o >3 o ) 和 α-电离基团离开能力 (TMS + >H + ) 会影响反应性。此外,发现使用 PhCHDNH 2 为基态反应测量的内部 d-同位素效应为 4.3,该值与在几乎相同(20 o C 而不是 80 o C) 条件
Controlling Selectivity in the Synthesis of
<i>Z</i>
‐α,β‐Unsaturated Amidines by Tuning the
<i>N</i>
‐Sulfonyl Group in a Rhodium(II) Catalyzed 1,2‐H Shift
作者:Matthew L. Martin、Alistair Boyer
DOI:10.1002/ejoc.202101235
日期:2021.11.22
α,β-Unsaturated amidines can be synthesized in high yield by rhodium(II) carboxylate catalyzed 1,2-H shift following denitrogenation of α-diazo amidines. Using a large carboxylate rhodium(II) ligand and an electron-poor N-sulfonyl group results in exclusive Z-selectivity and excellent yield by suppressing side reactions involving intramolecular oxygen transfer.
α-重氮脒脱氮后,羧酸铑(II)催化1,2-H转变,可以高产率合成α,β-不饱和脒。通过抑制涉及分子内氧转移的副反应,使用大的羧酸铑 (II) 配体和缺电子的N-磺酰基可实现独特的Z-选择性和优异的产率。
Mechanistic analysis of oxidative C–H cleavages using inter- and intramolecular kinetic isotope effects
作者:Hyung Hoon Jung、Paul E. Floreancig
DOI:10.1016/j.tet.2009.10.088
日期:2009.12
series of monodeuterated benzylic and allylic ethers were subjected to oxidative carbon–hydrogenbond cleavage to determine the impact of structural variation on intramolecular kinetic isotopeeffects in DDQ-mediated cyclization reactions. These values are compared to the corresponding intermolecular kinetic isotopeeffects that were accessed through subjecting mixtures of non-deuterated and dideuterated
Intermediacy of paramagnetic metal-hydrocarbyl species in organometallic reactions. Detection and characterization of a novel paramagnetic iron(II)-benzyl compound in the coupling of benzyl halides
作者:Dale H. Hill、Ayusman. Sen
DOI:10.1021/ja00213a063
日期:1988.3
authors report the detection and characterization by NMR spectroscopy of a novel paramagnetic Fe(II)-benzyl compound (TMEDA)Fe(CH/sub 2/Ph)/sub2/, which is the key intermediate in the coupling of benzyl halides by (CpFe(COD))(Li-(TMEDA)), (Cp = C/sub 5/H/sub5//sup -/, COD = 1,5-cyclooctadiene, TMEDA = Me/sub 2/N(CH/sub2/)/sub 2/NMe/sub2/).
Primary and secondary kinetic deuterium isotope effects and transition-state structures for benzylic chlorination and bromination of toluene
作者:Robert P. Hanzlik、Angela R. Schaefer、Joseph B. Moon、Charles M. Judson
DOI:10.1021/ja00250a028
日期:1987.8
chlorination of PhCH/sub 3/, PhCH/sub 2/D, PhCHD/sub2/, and PhCD/sub 3/ in a two-phase system of hypochlorite/CH/sub 2/Cl/sub2/ with a phase-transfer catalyst has been investigated. On the basis of the deuterium content of the product benzyl chlorides, relative rate constants were deduced for all possible H- and D-abstractions with these substrates. From this the primary (P) and secondary (S) KDIEs were found