Intramolecular CH Activation through Gold(I)-Catalyzed Reaction of Iodoalkynes
作者:Pablo Morán-Poladura、Eduardo Rubio、José M. González
DOI:10.1002/anie.201409970
日期:2015.3.2
NTf2=bis(trifluoromethanesulfonyl)imidate]. The reaction takes place in 1,2‐dichloroethane at 80 °C, and the addition of ttbp (2,4,6‐tri‐tert‐butylpyrimidine) is beneficial to accomplish this new transformation in high yield. The overall reaction implies initial assembly of an intermediate gold vinylidene upon alkyne activation by gold(I) and a 1,2‐iodine‐shift. Deuterium labeling and crossover experiments, the
Rhodium(II)-Catalyzed and Thermally Induced Intramolecular Migration of<i>N</i>-Sulfonyl-1,2,3-triazoles: New Approaches to 1,2-Dihydroisoquinolines and 1-Indanones
作者:Run Sun、Yu Jiang、Xiang-Ying Tang、Min Shi
DOI:10.1002/chem.201504914
日期:2016.4.11
New rhodium(II)‐catalyzed or thermally induced intramolecular alkoxy group migration of N‐sulfonyl‐1,2,3‐triazoles has been developed, affording divergent synthesis of 1,2‐dihydroisoquinoline and 1‐indanone derivatives according to different conditions. N‐Sulfonyl keteneimine is the key intermediate for the synthesis of dihydroisoquinoline, whereas the aza‐vinyl carbene intermediate results in the
Hetero Diels–Alder reactions of isolable N-borylenamines
作者:Pei Liang、Junhui Wei、Yongliang Wei、Xue Wang、Fei Liu、Tongdao Wang
DOI:10.1039/d4cc01645a
日期:——
N-borylenamines by reaction of 2-alkynyl benzyl azides with B(C6F5)3 was developed. This novel 1,3-carboboration reaction proceeded via a 5-exo-dig cyclization/formal 1,1-carboboration/B(C6F5)2 shift reaction sequence. Additionally, N-borylenamines can undergo heteroDiels–Alder (HDA) reactions with a variety of dienophiles. Our results are an attractive complement to HDA reactions.
开发了一种通过2-炔基苄基叠氮化物与B(C 6 F 5 ) 3反应制备N-亚硼基胺的新策略。这种新颖的1,3-碳硼化反应通过5- exo-dig环化/正式1,1-碳硼化/B(C 6 F 5 ) 2变换反应序列进行。此外, N-硼烯胺可以与多种亲双烯体发生杂狄尔斯-阿尔德(HDA)反应。我们的结果是对 HDA 反应的有吸引力的补充。
Discovery of a Photoinduced Dark Catalytic Cycle Using <i>in Situ</i> LED-NMR Spectroscopy
作者:Dan Lehnherr、Yining Ji、Andrew J. Neel、Ryan D. Cohen、Andrew P. J. Brunskill、Junyu Yang、Mikhail Reibarkh
DOI:10.1021/jacs.8b08596
日期:2018.10.24
We report the use of LED-NMR spectroscopy to study the reaction mechanism of a newly discovered photoinduced iron-catalyzed cycloisomerization of alkynols to cyclic enol ethers. By understanding on/off ligand binding to the catalyst, we were able to appropriately design reaction conditions to balance catalyst activity and stability. LED-NMR was demonstrated to be a powerful tool in elucidating reaction mechanisms of photochemical reactions. Temporal NMR spectroscopic data under visible light illumination (1) revealed the pre-catalyst activation mechanism, (2) proved that photon flux provides a unique external control of the equilibrium distribution between the pre-catalyst and active catalyst, and ultimately the rate of reaction, (3) provided information about the reaction driving forces and the turnover-limiting step, and (4) enabled both real-time structural and kinetic insights into elusive species (e.g., dissolved gases).