Long-acting contraceptive agents: Norethisterone esters of polyunsaturated acids
摘要:
Some new derivatives of norethisterone (17 alpha-ethynyl-17 beta-hydroxyestr-4-en-3-one) are described in which the 17 beta-hydroxyl group of the steroid is esterified with polyunsaturated aliphatic acids. The potential of these compounds as long-acting contraceptive agents has been evaluated.
A strategy for the β‐selective conjugate addition of α‐fluoro‐β‐ketoamides to allenicesters has been developed via phosphine catalysis and demonstrated for a wide range of ketoamides and allenoate substrates.
Substrate-controlled, PBu<sub>3</sub>-catalyzed annulation of phenacylmalononitriles with allenoates enables tunable access to cyclopentenes
作者:Narendra Kumar Vaishanv、Sanoop P Chandrasekharan、Mohd Khalid Zaheer、Ruchir Kant、Kishor Mohanan
DOI:10.1039/d0cc04688d
日期:——
phenacylmalononitriles with allenoates, controlled by the γ-substitution on allenoates, offers a tunable synthesis of multifunctionalized cyclopentene carboxamides and cyclopentenols. An unprecedented formation of cyclopentene carboxamide was observed when allenic esters bearing a substitution at the γ-position were employed, while unsubstituted allenoates produced cyclopentenols. The former reaction likely involves
We report the first directcatalyticasymmetric N1-functionalization of 1H-indoles via an allenylic alkylation strategy. This transformation produces N-alkylated indoles bearing axial chirality with a stereocenter non-adjacent (β) to the nitrogen. The regioselectivity (N1/C3) of this process can be switched efficiently. We also introduce a new class of tri-substituted allenylic electrophiles.
Small-Molecule Inhibitors of Protein Geranylgeranyltransferase Type I
作者:Sabrina Castellano、Hannah D. G. Fiji、Sape S. Kinderman、Masaru Watanabe、Pablo de Leon、Fuyuhiko Tamanoi、Ohyun Kwon
DOI:10.1021/ja070274n
日期:2007.5.1
Small molecules that inhibit the geranylgeranylation of K-Ras4B and RhoA by protein geranylgeranyltransferase type I (GGTase-I) were identified from chemical genetic screens of heterocycles synthesized through phosphine catalysis of allenes. To further improve the efficacy of the GGTase-I inhibitors (GGTIs), 4288 related compounds bearing core dihydropyrrole/pyrrolidine and tetrahydropyridine/piperidine scaffolds were synthesized on SynPhase lanterns in a split-pool manner through phosphine-catalyzed [3 + 2] and [4 + 2] annulations of resin-bound allenoates. Testing of the 4288 analogues resulted in several GGTIs exhibiting submicromolar IC50 values. Because proteins such as Ras and Rho GTPases are implicated in oncogenesis and metastasis, these GGTIs might ultimately lead to the development of novel antitumor therapeutics.
Iron Porphyrin-Catalyzed Olefination of Ketenes with Diazoacetate for the Enantioselective Synthesis of Allenes
作者:Chuan-Ying Li、Xiao-Bing Wang、Xiu-Li Sun、Yong Tang、Jun-Cheng Zheng、Zheng-Hu Xu、Yong-Gui Zhou、Li-Xin Dai
DOI:10.1021/ja068642v
日期:2007.2.1
In the presence of Ph3P and catalytic Fe(TCP) Cl, ketenes could react with EDA to give allenes in high yields under neutral conditions for the first time. By employing chiral phosphine instead of PPh3, allenes could be synthesized with high enantioselectivity (93-98% ee) in good yields.