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。
Simultaneous and Stereoselective Construction of Planar and Axial Centers of Chirality
作者:Louis Fogel、Richard P. Hsung、William D. Wulff、Roger D. Sommer、Arnold L. Rheingold
DOI:10.1021/ja010091f
日期:2001.6.1
all of these alkynes, the reaction products could be completely isomerized to the anti isomer by performing the reaction at 120 °C except for the smaller ortho methoxyl complex which only required 50 °C for complete conversion. This includes the very hindered tertbutyl complex3i which was formed as a slightly preferred kinetic product having the syn stereochemistry which was determined by X-ray diffraction
Aldol reactions of transition metal carbene complexes
作者:William D. Wulff、Scott R. Gilbertson
DOI:10.1021/ja00288a040
日期:1985.1
On presente les premiers exemples desreactionsdes anions «enolate» des complexes carbene des metaux de transition avec les composes carbonyle donnant des produits d'aldolisation. On etudie ainsi la condensation du complexe (CO) 5 Cr=C(OMe)CH 3 avec le phenyl-2 propanal
在presente les Premiers 示例des 反应des 阴离子«enolate» des complexes carbene des metaux de transition avec les composes carbonyle donnant des produits d'aldolisation。上 etudie ainsila condensation du complexe (CO) 5 Cr=C(OMe)CH 3 avec le phenyl-2 propanal
Palladium-Catalyzed [3+3] Annulation of Vinyl Chromium(0) Carbene Complexes through Carbene Migratory Insertion/Tsuji-Trost Reaction
作者:Kang Wang、Yifan Ping、Taiwei Chang、Jianbo Wang
DOI:10.1002/anie.201707590
日期:2017.10.9
Vinyl chromium(0) Fischer carbenecomplexes were employed as the source of π‐allylic palladium species for catalytic [3+3] annulation under palladium catalysis. Mechanistically, this transformation is proposed to involve carbene migratory insertion and intramolecular Tsuji–Trost reaction as the key steps. Substituted six‐membered heterocyclic flavonones and quinolines are obtained, depending on the
Alkyne Competition in the Benzannulation Reaction with Chromium Carbene Complexes
作者:Chunrui Wu、Dmytro O. Berbasov、William D. Wulff
DOI:10.1021/jo100433k
日期:2010.7.2
The benzannulation reaction of Fischer carbenecomplexes is investigated under conditions where the reaction of the carbenecomplex is occurring in the presence of two different alkynes. A series of competition experiments are examined where the effects of various structural factors are explored by pitting 10 different carbenecomplexes with 11 different alkynes. Terminal alkynes will react selectively