Cheap, readily available, air stable, nontoxic, and environmentally benign iron salts such as Fe(acac)3 are excellent precatalysts for the cross-coupling of Grignardreagents with alkenyl triflates and acid chlorides. Moreover, it is shown that dichloroarene and -heteroarene derivatives as the substrates can be selectively monoalkylated by this method. All cross-coupling reactions proceed very rapidly
廉价,容易获得,空气稳定,无毒且对环境无害的铁盐,例如Fe(acac)3是格氏试剂与链烯基三氟甲磺酸酯和酰氯交叉偶联的出色的预催化剂。此外,显示出通过该方法可以将作为底物的二氯亚芳基和-杂亚芳基衍生物选择性地单烷基化。所有交叉偶联反应在特别温和的条件下均能非常快速地进行,结果证明与两个反应伙伴中的各种官能团均相容。对制备结果的详细分析表明,铁催化的碳键形成可以通过不同的途径发生。因此,甲基卤化镁的反应可能包含铁酸盐配合物作为活性成分,而格氏试剂与两个或多个碳原子的反应则受到形式组成[Fe(MgX)2 ]的高度还原的铁簇的影响。n原位生成。使用复杂的[Me 4 Fe] Li 2的对照实验证实了这一解释。
Diastereodivergent Synthesis of β‐Amino Alcohols by Dual‐Metal‐Catalyzed Coupling of Alkoxyallenes with Aldimine Esters
作者:Minghui Zhu、Qinglong Zhang、Weiwei Zi
DOI:10.1002/anie.202014510
日期:2021.3.15
method for stereoselective access to complementary diastereomers would be highly desirable. Herein, we report a method for dual‐metal‐catalyzed diastereodivergent coupling of alkoxyallenes with aldimine esters. By carefully selecting the two metals and appropriate chiral ligands, we could synthesize both syn‐ and anti‐β‐amino alcohol motifs with high enantioselectivity and diastereoselectivity from the same
Remote Stereocontrol in [3,3]-Sigmatropic Rearrangements: Application to the Total Synthesis of the Immunosuppressant Mycestericin G
作者:Nathan W. G. Fairhurst、Mary F. Mahon、Rachel H. Munday、David R. Carbery
DOI:10.1021/ol203300k
日期:2012.2.3
3]-sigmatropic rearrangement has been used to access biologically important β,β′-dihydroxy α-amino acids. The rearrangement reported is highly stereoselective and offers excellent levels of remotestereocontrol. This strategy has been used to synthesize the natural immunosuppressant mycestericin G and ent-mycestericin G, allowing for a revision of absolute configuration of this natural product.
Chemoselectivity in the ruthenium-catalyzed redox isomerization of allyl alcohols
作者:Barry M. Trost、Robert J. Kulawiec
DOI:10.1021/ja00058a059
日期:1993.3
Adjustment of oxidation level by internalhydrogen reorganization represents a highly efficient synthetic protocol. Cyclopentadienylbis(triphenylphosphine)ruthenium chloride in the presence of triethylammonium hexafluorophosphate catalyzes the redox isomerization of allyl alcohols to their saturated aldehydes or ketones. High chemoselectivity is observed since simple primary and secondary alcohols