De novo syntheses of enantiopure glycosyl donors of D-/L-azapurpurosamine C type — enzymatic asymmetrizations
摘要:
Glycosyl donors of type 1 are synthesized starting from known cycloadducts of 1,3-cyclohexadiene with azo dienophiles and by utilizing biocatalytic asymmetrizations as access to the pure antipodes. Copyright (C) 1996 Elsevier Science Ltd
Novel Concerted Fragmentation upon Alcoholysis of a Urazole
作者:Yanjun Wei、David M. Lemal
DOI:10.1021/ol040051r
日期:2004.10.1
[reaction: see text] Instead of yielding the expected hydrazine, alcoholysis of the above heterocycle results in fragmentation via a highly unusual pathway.
meso-Diamino-di(tri,tetr)ols 1 – 8 were synthesized starting from cheap carbocyclic olefins and cis-diepoxy derivatives. Enantioselective hydrolysis of the corresponding bis(phenylacet)amides with penicillin amidase from E. coli (EC 3.5.1.11) was effected in good yields (73 – 90%) and with high optical purities (ee 91 − >97).
作者:Julian S. Kellner-Rogers、Rina Wang、Tristan H. Lambert
DOI:10.1021/acs.orglett.3c04309
日期:2024.2.9
The first platform for oxidative alkyl halide–olefin metathesis is described. The procedure employs diazenes as catalysts, which effect the cyclization of alkenyl alkylhalides to generate cyclic olefins and carbonyl products. The synthesis of phenanthrene, coumarin, and quinolone derivatives is demonstrated as well as the potential to apply this strategy to other electrophiles.