Synthesis of the marine alkaloids rhopaladins A, B, C and D
摘要:
The total synthesis of all four known rhopaladins, A-D, isolated from the Okinawan marine tunicate Rhopalaea sp., in two synthetic steps is described, involving an imidate based cyclization with tryptophan esters as the key step to afford the appropriately substituted imidazolinone unit. A short and efficient new synthesis of indol-3-yl-carbonyl nitriles from indol-3-yl-carboxaldehydes and trimethylsilyl cyanide, followed by oxidation with DDQ is also described. (C) 2002 Elsevier Science Ltd. All rights reserved.
Methyltriphenylphosphonium iodide catalyzes the addition of trimethylsilyl cyanide to aldehydes
作者:Rubén Córdoba、Joaquı́n Plumet
DOI:10.1016/s0040-4039(03)01391-1
日期:2003.8
Methyltriphenylphosphonium iodide catalyzes the formation of cyanohydrin trimethylsilyl ethers of aliphatic, aromatic and heterocyclic aldehydes.
甲基三苯基碘化碘催化脂肪族,芳香族和杂环醛的氰醇三甲基甲硅烷基醚的形成。
Hydroboration, Cyanosilylation, and Sequential Cyanosilylation and Hydroboration of Carbonyl Compounds in the Presence of a Ti<sup>IV</sup>
Amido Complex as an Efficient Catalyst
作者:Adimulam Harinath、Jayeeta Bhattcharjee、Koteswar Rao Gorantla、Bhabani S. Mallik、Tarun K. Panda
DOI:10.1002/ejoc.201800547
日期:2018.6.29
A titanium(IV) amido complex – [κ2‐(C5H4N)CH2NP(=Se)Ph2}Ti(NMe2)3] (1) – was synthesized and used as a catalyst for catalytic hydroboration, cyanosilylation, and sequential hydroboration/cyanosilylation of various aldehydes and ketones, with tolerance of a number of active functional groups, at ambient temperature. The mechanism was explored by kinetics study and theoretical calculations.
Alkali metal complexes as efficient catalysts for hydroboration and cyanosilylation of carbonyl compounds
作者:Adimulam Harinath、Jayeeta Bhattacharjee、Hari Pada Nayek、Tarun K. Panda
DOI:10.1039/c8dt02032a
日期:——
N-adamantyliminopyrolyl ligand 2-(AdNCH)–C4H3NH (L–H) and alkalimetal hexamethyldisilazides [MN(SiMe3)2] (M = Li, Na and K) to afford the dimeric [2-(AdNCH)–C4H3NLi(THF)}2] (1), [2-(AdNCH)–C4H3N}Na(THF)1.5}2] (2) and polymeric [2-(AdNCH)–C4H3NK(THF)}n] (3) complexes at ambient temperature. A one-pot reaction between L–H, [KN(SiMe3)2] and alkaline earth metal diiodide (AeI2) in a 2 : 2 : 1 molar ratio, which
我们在这里报告N-金刚烷基吡咯基配体2-(AdN CH)–C 4 H 3 NH(L–H)与碱金属六甲基二硅叠氮化物[MN(SiMe 3)2 ](M = Li,Na和K)之间的反应二聚体[2-(AdN CH)–C 4 H 3 NLi(THF)} 2 ](1),[2-(AdN CH)–C 4 H 3 N} Na(THF)1.5 } 2 ] (2)和聚合的[2-(AdN CH)–C 4 H 3 NK(THF)} n ](3)在环境温度下的配合物。L–H,[KN(SiMe 3)2 ]与碱土金属二碘化物(AeI 2)之间以2:2:1的摩尔比进行一锅反应,导致形成杂配Ae金属络合物[κ]还报告了2- 2-(AdN CH)–C 4 H 3 N} 2 Ae(THF)2 ] [Ae = Mg(4),Ca(5)]。复合物的固态结构1,3和4通过单晶X射线衍射分析来建立。碱金属和碱土金属配合物1-5被
Cellular Stress Upregulates Indole Signaling Metabolites in Escherichia coli
作者:Chung Sub Kim、Jhe-Hao Li、Brenden Barco、Hyun Bong Park、Alexandra Gatsios、Ashiti Damania、Rurun Wang、Thomas P. Wyche、Grazia Piizzi、Nicole K. Clay、Jason M. Crawford
DOI:10.1016/j.chembiol.2020.03.003
日期:2020.6
Escherichia coli broadly colonize the intestinal tract of humans and produce a variety of small molecule signals. However, many of these small molecules remain unknown. Here, we describe a family of widely distributed bacterial metabolites termed the "indolokines." In E. coli, the indolokines are upregulated in response to a redox stressor via aspC and tyrB transaminases. Although indolokine 1 represents a previously unreported metabolite, four of the indolokines (2-5) were previously shown to be derived from indole-3-carbonyl nitrile (ICN) in the plant pathogen defense response. We show that the indolokines are produced in a convergent evolutionary manner relative to plants, enhance E coli persister cell formation, outperform ICN protection in an Arabidopsis thaliana-Pseudomonas syringae infection model, trigger a hallmark plant innate immune response, and activate distinct immunological responses in primary human tissues. Our molecular studies link a family of cellular stress-induced metabolites to defensive responses across bacteria, plants, and humans.
Synthesis of the marine alkaloids rhopaladins A, B, C and D
作者:Tomasz Janosik、Ann-Louise Johnson、Jan Bergman
DOI:10.1016/s0040-4020(02)00171-0
日期:2002.4
The total synthesis of all four known rhopaladins, A-D, isolated from the Okinawan marine tunicate Rhopalaea sp., in two synthetic steps is described, involving an imidate based cyclization with tryptophan esters as the key step to afford the appropriately substituted imidazolinone unit. A short and efficient new synthesis of indol-3-yl-carbonyl nitriles from indol-3-yl-carboxaldehydes and trimethylsilyl cyanide, followed by oxidation with DDQ is also described. (C) 2002 Elsevier Science Ltd. All rights reserved.