Asymmetric Alcohol C–H Allylation and syn-Crotylation: C9–C20 of Tetrafibricin
摘要:
The C9-C20 segment of the fibrinogen receptor inhibitor tetrafibricin was prepared in 10 steps (longest linear sequence). Ruthenium catalyzed enantioselective syn-crotylation is used to construct C9-C13. Iridium catalyzed asymmetric alcohol C-H allylation of a commercial malic acid derived alcohol is used to construct C14-C20. Recovery and recycling of the iridium catalyst is described.
A Strategy for the Synthesis of Well-Defined Iron Catalysts and Application to Regioselective Diene Hydrosilylation
作者:Jessica Y. Wu、Benjamin N. Stanzl、Tobias Ritter
DOI:10.1021/ja106853y
日期:2010.9.29
the development of a well-defined Fe catalyst and its application to the regio- and stereoselective 1,4-hydrosilylation of 1,3-dienes. To the best of our knowledge, this is the first example of accessing a characterized low-valent Fe catalyst by controlled reductiveelimination from a readily accessible Fe precatalyst.
我们报告了明确定义的 Fe 催化剂的开发及其在 1,3-二烯的区域选择性和立体选择性 1,4-氢化硅烷化中的应用。据我们所知,这是第一个通过从易于获得的 Fe 预催化剂中受控还原消除来获得表征低价 Fe 催化剂的例子。
Stereochemical Characterization of Polyketide Stereotriads Synthesized via Hydrogen-Mediated Asymmetric <i>syn</i>-Crotylation
作者:Mathilde Pantin、Jonathan G. Hubert、Tilo Söhnel、Margaret A. Brimble、Daniel P. Furkert
DOI:10.1021/acs.joc.7b01820
日期:2017.10.20
The stereoselective access to stereotriads as important polyketide building blocks is reported on the basis of the Krische-type hydrogen-mediated syn-crotylation. The products were obtained with an extremely high diastereoselectivity (dr >99:1), and the newly formed syn stereocenters were controlled solely by the chiral catalyst. The stereochemistry was assigned by crystallography and HPLC for both
Total Synthesis of (+)-Trienomycins A and F via C–C Bond-Forming Hydrogenation and Transfer Hydrogenation
作者:David J. Del Valle、Michael J. Krische
DOI:10.1021/ja4061273
日期:2013.7.31
The triene-containing C17-benzene ansamycins trienomycins A and F were prepared in 16 steps (longest linear sequence, LLS) and 28 total steps. The C11-C13 stereotriad was generated via enantioselective Ru-catalyzed alcohol CH syn crotylation followed by chelation-controlled carbonyl dienylation. Enantioselective Rh-catalyzed acetylene-aldehyde reductive coupling mediated by gaseous H2 was used to form
含三烯的 C17-苯安沙霉素三烯霉素 A 和 F 以 16 个步骤(最长线性序列,LLS)和 28 个总步骤制备。C11-C13 立体三联体是通过对映选择性 Ru 催化的醇 CH 同步化生成,然后是螯合控制的羰基二烯化。由气态 H2 介导的对映选择性 Rh 催化乙炔-醛还原偶联用于形成二烯,该二烯最终经过二烯-二烯闭环复分解反应形成大环。本方法比以前合成的三烯霉素 A 和 F 短 14 步 (LLS),比任何以前合成的含三烯的 C17-苯安沙霉素短 8 步。
Diastereo- and Enantioselective Ruthenium-Catalyzed Hydrohydroxyalkylation of 2-Silyl-butadienes: Carbonyl<i>syn</i>-Crotylation from the Alcohol Oxidation Level
作者:Jason R. Zbieg、Joseph Moran、Michael J. Krische
DOI:10.1021/ja2046028
日期:2011.7.13
are converted to an equivalent set of adducts 4a-4j. Whereas reactions conducted usingconventional heating require 48 h, microwaveirradiation enables full conversion in only 4 h. Finally, as illustrated in the conversion of adduct 4a to compounds 6a and 6b, diastereoselective hydroboration-Suzuki cross-coupling with aryl and vinyl halides followed by Fleming-Tamao oxidation enables generation of anti
Total Synthesis of the Acetyl CoA Carboxylase Inhibitor Soraphen A: Asymmetric Tsuji Reduction Enables Successive Olefin Metathesis
作者:Tabitha T. Schempp、Michael J. Krische
DOI:10.1021/jacs.1c12063
日期:2022.1.19
The total synthesis of soraphen A, a myxobacterial metabolite and inhibitor of acetyl CoA carboxylase, was completed in 11 steps (longestlinearsequence), less than half the steps previously required. Seven metal-catalyzed processes were deployed to unlock step-economy (comprising five asymmetric processes and four C–C bond formations). The present route does not utilize chiral auxiliaries, and four
粘细菌代谢物和乙酰辅酶 A 羧化酶抑制剂 soraphen A 的全合成在 11 个步骤(最长的线性序列)中完成,不到以前所需步骤的一半。部署了七个金属催化过程来解锁步骤经济(包括五个不对称过程和四个 C-C 键形成)。目前的路线不使用手性助剂,五个 C-C 键形成中的四个利用非预金属化伙伴。为了最大化收敛性,使用 Pd-AntPhos 催化剂开发了不对称 Tsuji 还原,该催化剂允许复分解不活泼的烯丙基碳酸酯充当掩蔽的末端烯烃,从而实现连续的烯烃复分解事件。