四唑并[1,5- b ]哒嗪8T的温和快速真空热解会生成少量的3-叠氮基哒嗪8A(8aA,IR 2145,2118 cm –1;8bA,2142 cm –1)。在Ar基质中对四唑/叠氮化物8T / 8A进行光解会生成3-吡啶并氮杂氮基9,通过ESR光谱法检测到(9a:D / hc = 1.006;E / hc = 0.003 cm –1)。Cyanovinylcarbenes 11,由4- diazobut -2- enenitriles衍生10,也可以通过ESR光谱法检测(11a:D / hc = 0.362;E / hc = 0.021 cm –1)。卡宾11重排为氰基亚勒烯12和3-氰基环丙烯13。在8的光解中未观察到三氮杂七庚烯20。在254 nm的Ar矩阵中对四唑并[1,5- a ]嘧啶/ 2-叠氮基吡啶18T / 18A进行光解可得到2-嘧啶基亚硝酸19,可通过ESR,UV和IR光谱法观察到(19a:ESR:D
四唑并[1,5- b ]哒嗪8T的温和快速真空热解会生成少量的3-叠氮基哒嗪8A(8aA,IR 2145,2118 cm –1;8bA,2142 cm –1)。在Ar基质中对四唑/叠氮化物8T / 8A进行光解会生成3-吡啶并氮杂氮基9,通过ESR光谱法检测到(9a:D / hc = 1.006;E / hc = 0.003 cm –1)。Cyanovinylcarbenes 11,由4- diazobut -2- enenitriles衍生10,也可以通过ESR光谱法检测(11a:D / hc = 0.362;E / hc = 0.021 cm –1)。卡宾11重排为氰基亚勒烯12和3-氰基环丙烯13。在8的光解中未观察到三氮杂七庚烯20。在254 nm的Ar矩阵中对四唑并[1,5- a ]嘧啶/ 2-叠氮基吡啶18T / 18A进行光解可得到2-嘧啶基亚硝酸19,可通过ESR,UV和IR光谱法观察到(19a:ESR:D
Selective radical amination of aldehydic C(sp<sup>2</sup>)–H bonds with fluoroaryl azides via Co(<scp>ii</scp>)-based metalloradical catalysis: synthesis of N-fluoroaryl amides from aldehydes under neutral and nonoxidative conditions
作者:Li-Mei Jin、Hongjian Lu、Yuan Cui、Christopher L. Lizardi、Thiago N. Arzua、Lukasz Wojtas、Xin Cui、X. Peter Zhang
DOI:10.1039/c4sc00697f
日期:——
proven to be an effective metalloradical catalyst for intermolecularamination of C(sp2)–H bonds of aldehydes with fluoroaryl azides. The [Co(P1)]-catalyzed process can employ aldehydes as the limiting reagents and operate under neutral and nonoxidative conditions, generating nitrogen gas as the only byproduct. The metalloradical aldehydic C–H amination is suitable for different combinations of aldehydes
D 2h对称酰胺卟啉 3,5-Di t Bu-IbuPhyrin [Co( P1 )]的 Co( II ) 配合物已被证明是一种有效的金属基催化剂,用于 C(sp 2 )–H 键的分子间胺化醛与氟芳基叠氮化物。[Co( P1 )]-催化过程可以使用醛作为限制试剂并在中性和非氧化条件下运行,产生氮气作为唯一的副产品。金属基醛 C-H 胺化适用于醛和氟芳基叠氮化物的不同组合,产生相应的N-氟芳基酰胺的产率非常好。一系列机理研究支持 Co( II ) 催化的分子间 C-H 胺化的逐步自由基机制。
Synthesis and Biological Evaluation of Oleanolic Acid Derivatives as Selective Vascular Endothelial Growth Factor Promoter i-Motif Ligands
作者:Huang Zeng、Shuangshuang Kang、Yu Zhang、Ke Liu、Qian Yu、Ding Li、Lin-Kun An
DOI:10.3390/ijms22041711
日期:——
for the development of selectiveligands of VEGF i-motif. A series of oleanolic acid derivatives as VEGF promoter i-motif ligands were synthesized. Subsequent evaluations showed that 3c could selectively bind to and stabilize VEGF promoter i-motif without significant binding to G-quadruplex, duplex DNA, and other oncogene i-motifs. Cell-based assays indicated that 3c could effectively downregulate VEGF
A Matrix Isolation Spectroscopy and Laser Flash Photolysis Study of 2-Pyrimidylnitrene
作者:Monica Cerro-Lopez、Nina P. Gritsan、Zhendong Zhu、Matthew S. Platz
DOI:10.1021/jp0021401
日期:2000.11.1
calculations agree that cyclization of singlet 2-pyrimidylnitrene to form a 1H-benzodiazirine is more endothermic than the corresponding process in unsubstituted singletphenylnitrene if the singlet -triplet gaps of the two nitrenes are comparable. The rate constant of intersystem crossing of 1 PN is more than 200 times faster than that of parent singletphenylnitrene. Cyclization of 1 PN to the benzo 1H-diazirine
2-叠氮嘧啶 (AP) 在 77 K 的玻璃状乙醇 (EtOH) 中的光解 (254 nm) 产生 2- 嘧啶基氮 (D ) 1.15 cm -1 ) 三重基态的 EPR 光谱。AP 在 EtOH 中在 77 K 的光解 (254 nm) 导致叠氮化物 (Imax) 的吸收漂白 (Imax) 242 nm) 并形成 300 和 400 nm 之间的宽吸收带和 400 和 450 nm 之间的高度结构化带。通过在 14 K 的氩气中光解 AP 观察到更高分辨率但相似的光谱。这些带在氩气中的出现伴随着一系列 IR 跃迁的形成。实验观察到的红外光谱与密度泛函理论以6-31G*基组预测的三重态2-嘧啶基氮烯( 3 PN)的光谱一致。根据 IR 和 EPR 结果,UV-vis 光谱归因于 3 PN。在环境温度下,AP 在二氯甲烷中的激光闪光光解 (LFP) 产生 3 PN,其特征结构吸收在 400 和
STANOVNIK B.; TISLER M.; POLANC S.; KOVACIC-BRATINA V.; SPICER-SMOLNIKAR +, TETRAHEDRON LETT. <TELE-AY>, 1976, NO 36, 3193-3196