Synthesis of chromium N-heterocyclic carbene complexes using chromium Fischer carbenes as a source of chromium carbonyls
作者:Seongjin Kim、Soo Young Choi、Young Tak Lee、Kang Hyun Park、Helmut Sitzmann、Young Keun Chung
DOI:10.1016/j.jorganchem.2007.08.043
日期:2007.11
Chromium Fischer carbenecomplexes, [CrOMe(R)}(CO)5] have been utilized as a source of chromium carbonyls in the synthesis of chromium NHC complexes. Using the synthetic method, chromiumcomplexes of various NHC ligands were isolated in reasonable yields. Moreover, the method can be employed for the synthesis of molybdenum and tungsten NHC compounds.
Simultaneous Synthesis of Both Rings of Chromenes via a Benzannulation/<i>o</i>-Quinone Methide Formation/Electrocyclization Cascade
作者:Nilanjana Majumdar、Keith A. Korthals、William D. Wulff
DOI:10.1021/ja210655g
日期:2012.1.18
A new route to the chromene ring system has been developed which involves the reaction of an α,β-unsaturated Fischer carbenecomplex of chromium with a propargyl ether bearing an alkenyl group on the propargylic carbon. This transformation involves a cascade of reactions that begins with a benzannulation reaction and is followed by the formation of an o-quinone methide, and finally results in the emergence
开发了一种色烯环体系的新路线,该路线涉及铬的α,β-不饱和费歇尔卡宾络合物与在炔丙碳上带有烯基的炔丙醚的反应。这种转化涉及一系列反应,从苯并环化反应开始,然后形成邻醌甲基化物,最后在电环化时产生色烯。通过使用芳基卡宾络合物,该反应被扩展以提供通路。这是色烯的首次合成,其中色烯系统的两个环均在一步中生成,并在 lapachenole 和维生素 E 的合成中得到突出体现。
Synthesis of Naphthalenes through Three-Component Coupling of Alkynes, Fischer Carbene Complexes, and Benzaldehyde Hydrazones via Isoindole Intermediates
作者:Shaofeng Duan、Dilip K. Sinha-Mahapatra, and、James W. Herndon
DOI:10.1021/ol800242n
日期:2008.4.1
The synthesis of naphthalene derivatives through three-component coupling of 2-alkynylbenzaldehyde hydrazones with carbene complexes and electron-deficient alkynes has been examined. The reaction involves formation of an isoindole derivative, followed by intramolecular Diels-Alder reaction, followed by nitrene extrusion. The reaction was highly regioselective using unsymmetrical alkynes.
New Method for the Preparation of Alkoxycarbene Complexes of Chromium, Molybdenum, and Tungsten Using Sulfonium Salts
作者:Takako Nakamura、Haruo Matsuyama、Masahiko Iyoda
DOI:10.1246/cl.1994.1537
日期:1994.8
Alkylation of tetramethylammonium acylate complexes of chromium, molybdenum, and tungsten with alkyldiphenylsulfonium salts readily proceeds under mild conditions to afford alkoxycarbene complexes containing a variety of functional groups in good yields.
Fischer Carbene Pentannulation with Alkynes Having Adjacent Carbonate or Acyloxy Groups: Synthesis of 3-Substituted 1-Indanones
作者:Rodney A. Fernandes、Sachin P. Gholap、Vijay P. Chavan、Akeel S. Saiyed、Shubhankar Bhattacharyya
DOI:10.1021/acs.orglett.0c00901
日期:2020.5.1
Various aryl Fischercarbenes reacted with alkynes having adjacent acyloxy or carbonate groups to regioselectively deliver 3-substituted 1-indanones. The acyloxy or carbonate group probably coordinates with the Cr metal to give a tetra-coordinated chromium complex forming a six-membered ring that retards CO insertion for ketene formation, which is required for benzannulation. Alternatively, the ortho