Reductive Lithiation of Methyl Substituted Diarylmethylsilanes: Application to Silanediol Peptide Precursors
摘要:
Reductive lithiation of methyl-substituted diarylmethylsilanes using lithium naphthalenide represents a practical method for the preparation of the corresponding sillyl lithium reagents. Their addition to chiral sulfinimines affords versatile precursors to silanols and silanediols. The replacement of the currently used diphenylsilane motif by a more labile diarylsilane moiety allows the selective hydrolysis of one or two aryl groups by treatment with TFA.
Catalytic Asymmetric SiO Coupling of Simple Achiral Silanes and Chiral Donor-Functionalized Alcohols
作者:Andreas Weickgenannt、Marius Mewald、Thomas W. T. Muesmann、Martin Oestreich
DOI:10.1002/anie.200905561
日期:2010.3.15
Silicon alley: SiH and HOR are enantioselectively coupled in the presence of a chiral CuH complex. In this way, the kinetic resolution of racemic mixtures of alcohols is accomplished through asymmetric protection with standard silanes (see scheme; R=aryl or alkyl, Ar=3,5‐xylyl, Np=2‐naphthyl; s=selectivity factor).
硅胡同:硅 H和H 或者,对映选择性地耦合在手性铜的存在 H络合物。通过这种方式,醇的外消旋混合物的动力学拆分可通过使用标准硅烷进行不对称保护来实现(参见方案; R =芳基或烷基,Ar = 3,5-二甲苯基,Np = 2-萘基; s =选择性因子)。
Silylcarboxylic Acids as Bifunctional Reagents: Application in Palladium‐Catalyzed External‐CO‐Free Carbonylative Cross‐Coupling Reactions
作者:Xiong Li、Jie Xu、Yue Li、Søren Kramer、Troels Skrydstrup、Zhong Lian
DOI:10.1002/adsc.202000586
日期:2020.10.6
palladium‐catalyzed external‐CO‐free carbonylative Hiyama‐Denmark cross‐couplingreaction is presented. The introduction of silylcarboxylic acids as bifunctionalreagents (CO and nucleophile source) avoids the need for external gaseous CO and a silylarene coupling partner. The transformation features high functional group tolerance and it is successful with electron‐rich, ‐neutral, and ‐poor aryl iodides. Stoichiometric
(with silicon-stereogenic silanes) and enantioselective (with achiral silanes) Si–O couplings of azine donor-functionalized alcohols. The limitation, that is, the requirement of a nitrogen donor atom, prompted us to seek equally useful donor groups. Oxime ethers were identified as a suitable alternative, and we describe herein the preparation of a series of oxime ether-functionalized alcohols. To assess
Organocalcium Complex-Catalyzed Selective Redistribution of ArSiH<sub>3</sub> or Ar(alkyl)SiH<sub>2</sub> to Ar<sub>3</sub>SiH or Ar<sub>2</sub>(alkyl)SiH
作者:Tao Li、Karl N. McCabe、Laurent Maron、Xuebing Leng、Yaofeng Chen
DOI:10.1021/acscatal.1c00463
日期:2021.6.4
compounds. Herein, we report the synthesis and structural characterization of two calcium alkyl complexessupported by β-diketiminato-based tetradentate ligands. These two calcium alkyl complexes react with PhSiH3 to generate calcium hydrido complexes, and the stability of the hydrido complexes depends on the supportingligands. One calcium alkyl complex efficiently catalyzes the selective redistribution
Construction of siloxane structures with P-Tolyl substituents at the silicon atom
作者:Sergey A. Milenin、Sofia N. Ardabevskaia、Roman A. Novikov、Pavel N. Solyev、Yaroslav V. Tkachev、Alexander D. Volodin、Alexander A. Korlyukov、Aziz M. Muzafarov
DOI:10.1016/j.jorganchem.2020.121497
日期:2020.11
In this work, general approaches for preparing p-tolylsilanes as promising precursors for the synthesis of functionalized organosilicon compounds are discussed. Various synthetic techniques, including new and specially developed ones, were used to obtained p-tolylsiloxanes of different structures. Our findings resulted in advanced methods over the previously reported procedures, since they do not imply