Dechalcogenative Allylic Selenosulfide and Disulfide Rearrangements: Complementary Methods for the Formation of Allylic Sulfides in the Absence of Electrophiles. Scope, Limitations, and Application to the Functionalization of Unprotected Peptides in Aqueous Media
作者:David Crich、Venkataramanan Krishnamurthy、Franck Brebion、Maheswaran Karatholuvhu、Venkataraman Subramanian、Thomas K. Hutton
DOI:10.1021/ja072969u
日期:2007.8.1
Primary allylic selenosulfates (seleno Bunte salts) and selenocyanates transfer the allylic selenide moiety to thiols giving primary allylic selenosulfides, which undergo rearrangement in the presence of PPh3 with the loss of selenium to give allylically rearranged allyl alkylsulfides. This rearrangement may be conducted with prenyl-type selenosulfides to give isoprenyl alkylsulfides. Alkyl secondary
Based on crystallographic data of the complexes 2-alkyl(amino)ethyl-1,1-bisphosphonates–Trypanosoma cruzi farnesyl diphosphate synthase, some linear 1,1-bisphosphonic acids and other closely related derivatives were designed, synthesized and biologically evaluated against T. cruzi, the responsible agent of Chagas disease and against Toxoplasma gondii, the etiologic agent of toxoplasmosis and also towards the target enzymes farnesyl pyrophosphate synthase of T. cruzi (TcFPPS) and T gondii (TgFPPS), respectively. The isoprenoid-containing 1,1-bisphosphonates exhibited modest antiparasitic activity, whereas the linear α-fluoro-2-alkyl(amino)ethyl-1,1-bisphosphonates were unexpectedly devoid of antiparasitic activity. In spite of not presenting efficient antiparasitic activity, these data turned out to be very important to establish a structural activity relationship.
Dialdehyde compound, preparation method thereof, and synthetic method of carotenoids using the same
申请人:Koo Sang Ho
公开号:US20090318732A1
公开(公告)日:2009-12-24
The novel C dialdehyde compound which can be efficiently utilized in the synthesis of carotenoid compounds based on the sulfone chemistry, the preparation method of the same, and the expeditious and practical synthetic processes for lycopene and β-carotene by the use of the above novel compound are disclosed. The syntheses of lycopene and β-carotene are characterized by the processes of the coupling reaction between two equivalents of geranyl sulfone or cyclic geranyl sulfone and the above C dialdehyde, the functional group transformation reactions of the diol in the resulting C 40 coupling products to X's (either halogens or ethers), and the double elimination reactions of the functional groups of the benzenesulfonyl and X to produce the fully conjugated polyene chain of the carotenoids.
Homologated aza analogs of arabinose as antimycobacterial agents
作者:Joseph A. Maddry、Namita Bansal、Luiz E. Bermudez、Robert N. Comber、Ian M. Orme、William J. Suling、Larry N. Wilson、Robert C. Reynolds
DOI:10.1016/s0960-894x(98)00017-1
日期:1998.2
A series of hydrolytically-stable aza analogs of arabinofuranose was prepared and evaluated against Mycobacterium tuberculosis and M. avium. The compounds were designed to mimic the putative arabinose donor involved in biogenesis of the essential cell wall polysaccharide, arabinogalactan. Though most compounds displayed little activity in cell culture, one compound showed significant activity in infected
Generation of α-phosphonovinyl radicals and development of a new route to highly functionalized vinylphosphonates and vinylphosphonate-incorporated carbocyclic or heterocyclic compounds via a radical trapping sequence
of synthetically useful alpha-phosphonovinyl radicals was achieved by treatment of alpha-phosphonovinyl halides with a tributyltin radical. The alpha-phosphonovinyl radicals 2a-d were trapped with electron-rich olefins and an electron-deficient olefin to produce alpha-functionalized vinylphosphonates 3a-f in 16-55% yields. The alpha-phosphonovinyl radicals 7e-g containing the YCH2CH=CH2 (Y = O, CH2,