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.
Pd-catalyzed Oxidative Cross-coupling of Alkyl Chromium(0) Fischer Carbene Complexes with Organoboronic Acids
作者:Kang Wang、Jinghui Yang、Xingqi Yao、Jianbo Wang
DOI:10.1002/asia.201801278
日期:2018.11.2
Alkyl chromium(0) carbenecomplexes have been explored as the cross‐coupling partners in the palladium‐catalyzed reaction with aryl or alkenyl boronic acids. This coupling reaction displays the versatile reactivities of alkyl chromium(0) carbenes under palladium catalysis. Mechanistically, this transformation is proposed to involve deprotonation of the alkyl chromiumcarbene substrate to generate a
Pd-Catalyzed Cross-Coupling of Terminal Alkynes with Chromium(0) Fischer Carbene Complexes
作者:Kang Wang、Fengjin Wu、Yan Zhang、Jianbo Wang
DOI:10.1021/acs.orglett.7b01096
日期:2017.6.2
Alkyl chromium(0) carbenecomplexes typically undergo cycloadditions with alkynes to afford carbo- or heterocyclic compounds. In the presence of Pd catalyst, it is demonstrated that a traditional cycloaddition pathway is completely altered: instead of cycloaddition, oxidative cross-coupling reaction of alkyl chromium(0) carbenecomplexes with terminal alkynes occurs. The coupling reaction exhibits
Stereoselective Formation of (E)-β-Alkoxy Acrylates from Fischer Carbene Complexes and Chelated Amino Acid Ester Enolates
作者:Uli Kazmaier、Rupsha Chaudhuri
DOI:10.1055/s-0033-1340496
日期:——
Chelated amino acid esterenolates react with alkyl Fischer carbene complexes via nucleophilic attack on the electrophilic carbene center. Subsequent elimination of the metal fragment and trifluoroacetamide results in the formation of β-alkoxy-α,β-unsaturated esters in a highly E -stereoselective fashion.
Synthesis of optically active ene carbamates from chromium carbene complexes: use in palladium(II)-assisted synthesis of relays to (+)-thienamycin
作者:John Montgomery、Gary M. Wieber、Louis S. Hegedus
DOI:10.1021/ja00173a012
日期:1990.8
prepare opticallyactivechromium carbene complexes containing the oxazolidinone moiety led instead to an efficient and general synthesis of opticallyactive ene carbamates. One of these has been subjected to palladium(II)-assisted carboacylation, and complete control of stereochemistry was observed. This compound was converted to a key relay to (+)-thienamycin in good chemical and very high optical yield
尝试制备含有恶唑烷酮部分的光学活性铬卡宾配合物,反而导致了光学活性烯氨基甲酸酯的有效和通用合成。其中之一已进行钯 (II) 辅助的碳酰化,并观察到立体化学的完全控制。该化合物以良好的化学和非常高的光学产率转化为 (+)-硫霉素的关键中继