Several new chiral bipyridyldiol ligands that promote the chromium-catalyzedenantioselective addition of allylic halides to aldehydes in up to 99% ee were synthesized. The chromium-catalyzed allylation of aldehydes using ligands 4 and 4a in the presence of chromium(III) chloride and allyl chloride provided the highest enantioselectivity.
Assessment of the regioselectivity in the condensation reaction of unsymmetrical o -phthaldialdehydes with alanine
作者:Agathe C.A. D'Hollander、Nicholas J. Westwood
DOI:10.1016/j.tet.2017.11.035
日期:2018.1
context of the use of o-phthaldialdehydes that contain additional substituents in the aromatic ring leading to a detailed analysis of the regioselectivity of the reaction. Eleven monosubstituted o-phthaldialdehydes were synthesised and reacted with alanine. The regioselectivity observed across the eleven substrates led to the design of a disubstituted substrate that reacted with very high control. A gram-scale
Synthetic approaches to the alkaloids of the ancistrocladaceae: control of the diastereoisomer excess in the synthesis of axially chiral biaryls: a synthesis of (–)-ancistrocladinine
作者:Mark A. Rizzacasa、Melvyn V. Sargent
DOI:10.1039/c39910000278
日期:——
control the diastereoisomeric excess in the reactions of 2,6-disubstituted phenyl Grignard reagents with the naphthyloxazoline 2; advantage is taken of the results in a synthesis of the Ancistrocladus alkaloid (–)-ancistrocladinine 19.
Enantioselective Iridium-Catalyzed Phthalide Formation through Internal Redox Allylation of Phthalaldehydes
作者:James M. Cabrera、Johannes Tauber、Michael J. Krische
DOI:10.1002/anie.201712015
日期:2018.1.26
An inside job: Enantioselective phthalide synthesis was achieved through internal redox allylation of o‐phthalaldehydes. Oxidative esterification is balanced by reductive carbonyl addition to achieve an overall redox‐neutral process. This method enabled formal syntheses of ent‐spirolaxine methyl ether and CJ‐12,954.
One-Photon and/or Two-Photon Fluorescent Probe for Sensing Hydrogen Sulfide, Imaging Method of Hydrogen Sulfide Using Same, and Manufacturing Method Thereof
申请人:POSTECH ACADEMY-INDUSTRY FOUNDATION
公开号:US20160274123A1
公开(公告)日:2016-09-22
The present invention relates to a one-photon and/or two-photon fluorescent probe for selectively detecting hydrogen sulfide in the human body using a compound including an α,β-unsaturated carbonyl group and an acedan (2-acyl-6-dimethyl-amino-naphthalene) fluorescent material; to an imaging method of hydrogen sulfide in cells using the same; and to a manufacturing method of the fluorescent probe. More specifically, in the fluorescent probe of the present invention, the α,β-unsaturated carbonyl group of the compound selectively binds to hydrogen sulfide, inducing an increase in fluorescence of the acedan fluorescent material. The fluorescent probe according to the present invention can be conveniently synthesized, enables two-photon excitation, and corresponds to a small-molecule probe having stability and low toxicity in the body. In addition, the fluorescent probe according to the present invention can exhibit a fluorescent change by selectively reacting with hydrogen sulfide, thereby imaging the distribution of hydrogen sulfide in cells or tissues, and thus can be useful for a composition for imaging and an imaging method.