A Modular Synthetic Approach toward Exhaustively Stereodiversified Ligand Libraries
摘要:
This report describes a modular approach to the synthesis of stereodiversified natural product like libraries. Monomers 2 and 3 were coupled in parallel by silyl tethered olefin metathesis to generate all 16 stereoisomers of cis-enediols 1. All 16 stereoisomers were incorporated into chimerae having flanking peptidic segments. These chimerae exhibited a broad range of hydrophobicities, raising the possibility that stereochemical variation might be used to tune the pharmacologic properties of small molecules.
Synthesis of indolin-2-ones (oxindoles) related to mitomycin A
作者:Ralph A. Raphael、Paul Ravenscroft
DOI:10.1039/p19880001823
日期:——
Oxindoles (Indolin-2-ones) containing the functionality of the first two rings of the mitomycin A structure have been synthesized. Attempts to employ the oxindole grouping to construct the third ring were unsuccessful because of the resistance of the oxindole group or its derivatives towards nucleophilic attack. An unusual methylation of 3-methyl-5-nitrobenzene-1,2,4-triol to give the (E)-3,6-dihydroxy-2-methyl-1
The chemistry of alkyl thiosulfinate esters. 9. Antithrombotic organosulfur compounds from garlic: structural, mechanistic, and synthetic studies
作者:Eric. Block、Saleem. Ahmad、James L. Catalfamo、Mahendra K. Jain、Rafael. Apitz-Castro
DOI:10.1021/ja00282a033
日期:1986.10
Synthese de l'ajoene (oxyde-9 de trithia-4,5,9 dodecatriene-1,6,11) et de quelques analogues
合成 de l'ajoene (oxyde-9 de trithia-4,5,9 dodecatriene-1,6,11) et de quelques 类似物
<i>C</i><sub>2</sub>-Symmetric Cu(II) Complexes as Chiral Lewis Acids. Catalytic, Enantioselective Cycloadditions of Silyl Ketenes
作者:David A. Evans、Jacob M. Janey
DOI:10.1021/ol016096z
日期:2001.6.1
[reaction: see text] C(2)-Symmetric bis(oxazoline)-Cu(II) complexes (4a-g) catalyze the enantioselective [2 + 2] cycloaddition between (silyl)ketenes and chelating carbonyl substrates. A range of substituted beta-lactones can be produced in excellent yields and selectivities. It was also found that (trimethylsilyl)ketene (1) may also undergo a highly selective hetero Diels-Alder reaction with beta
A convenient stereoselective synthesis of β-lactams from β-hydroxy-α-thioalkylesters prepared from Michael/aldol tandem reaction or stereoselective addition of thiols to the Baylis–Hillman adducts
A convenient stereoselective synthesis of β-lactams from thio-Michael/aldol tandem adduct is described. syn-Selective tandem reaction followed by amidation and intramolecular SN2 reaction provided β-lactams in diastereomerically pure form. The tandem reaction with aliphatic aldehydes, on the other hand, afforded a mixture of diastereomers of corresponding tandem adducts in about 3:1 ratio so that the
描述了由硫代迈克尔-迈克尔/醛醇双键加合物方便地立体选择性合成β-内酰胺。syn-选择性串联反应,然后进行酰胺化和分子内S N 2反应,提供非对映体纯形式的β-内酰胺。另一方面,与脂族醛的串联反应以约3∶1的比例提供了相应的串联加合物的非对映异构体的混合物,使得转化为β-内酰胺提供了非对映异构体的混合物。作为制备串联加合物的另一种方法,开发了将脂肪族硫醇立体选择性迈克尔加成到Baylis-Hillman加合物中的方法。立体选择性对羟基上的保护基敏感,TBS保护带来了最成功的合成选择性形成串联加合物。该方法可用于Baylis-Hillman加合物的酮衍生物,但未观察到腈-Baylis-Hillman加合物的选择性。加合物的类似转化立体选择性地提供了所需的β-内酰胺。
An improved route to the synthesis of µ-(alkane- or arene-thiolato)(µ-ethenyl)di-iron complexes. Crystal structure of µ-phenylmethanethiolato-µ-(1,2-diphenylethenyl)-hexacarbonyldi-iron(Fe–Fe)
作者:Josep Ros、Josep M. Viñas、René Mathieu、Xavier Solans、Mercé Font-Bardía
DOI:10.1039/dt9880000281
日期:——
CH2Ph) lead to the complexes [Fe2(CO)6(µ-SR)(µ-CPhCHPh)]. The structure of the benzyl derivative has been established by X-ray diffraction methods; crystals are monoclinic, space group P21/n with a= 21.383(3), b= 7.098(2), c= 16.856(3), Å, β= 95.49(2)°, and Z= 4. The structure was solved and refined on the basis of 2 197 significant counter data, to a final R value of 0.056. The structure consists of Fe2(CO)6