The invention provides novel six and seven-carbon termini-differentiated polypropionate stereotetrads and stereopentads useful in syntheses of natural products. The invention also provides a novel alkylative sulfenylation-desulfonylation process that efficiently transforms enantiopure epoxyvinyl sulfones to syn and anti dienylsulfides in two operations.
Fused-ring alkane fuel and photocatalytic preparation process thereof
申请人:TIANJIN UNIVERSITY
公开号:US20200181040A1
公开(公告)日:2020-06-11
A process for preparing a fused-ring alkane fuel, wherein the fused-ring alkane fuel has the following structure:
wherein n is 1 or 2; R
1
, R
2
, R
3
, R
4
and R
5
are H or —CH
3
or —CH
2
CH
3
;
the fused-ring alkane fuel has a density of greater than 0.870 g/cm
3
, a freezing point of not higher than −50° C., and a net mass heat value of not less than 42.0 MJ/kg; the process for preparing a fused-ring alkane fuel, wherein the process includes steps of: (1) in a presence of ultraviolet light and a photocatalyst, a Diels-Alder cycloaddition reaction between a substituted or unsubstituted cyclic enone and a substituted or unsubstituted furan molecule occurs to produce a fuel precursor molecule:
(2) the fuel precursor molecule obtained in the step (1) is subjected to hydrodeoxygenation to produce the fused-ring alkane fuel.
On prepare plusieurs systemes contenant deux olefines electrophiles, l'une etant une cetone α-methylene, l'autre un ester α,β-insature. L'addition de Michael de l'enolate de lithium du trimethylsiloxy-2methyl-3butene-1 sur ces systemes, suivie d'une addition intramoleculaire de Michael, conduit a la formation du systeme tricyclique a 3 noyaux en C 6 . On a pu ainsi obtenir le dimethyl-3aflavinine
在制备plusieurs systemes contenant deux 烯烃亲电试剂,l'une etant une cetone α-methylene, l'autre un酯α,β-insature。L'addition de Michael de l'enolate delithium du trimethylsiloxy-2methyl-3butene-1 sur ces systemes, suvie d'une加成intramoleculaire de Michael, 管道系统三环a 3 noyaux en C 6 。对 pu ainsi obtenir le dimethyl-3aflavinine
Total Synthesis of (−)-Chiloscyphone, Sesquiterpenoid Isolated from the Liverwort. Absolute Configuration of (−)-Chiloscyphone and (+)-Chiloscypholone
作者:Motoo Tori、Takeshi Hasebe、Yoshinori Asakawa
DOI:10.1246/bcsj.63.1706
日期:1990.6
The absolute configurations of (−)-chiloscyphone and (+)-chiloscypholone isolatedfrom the liverwort Chiloscyphus polyanthos and C. pallescens respectively, have been determined by the total synthesis of the optically active compound. The 1,4-addition of vinylmagnesium bromide to 3,4-dimethyl-2-cyclohexenone in the presence of copper(I) bromide-dimethyl sulfide complex and the subsequent aldol condensation
Multifunctional biocatalyst for conjugate reduction and reductive amination
作者:Thomas W. Thorpe、James R. Marshall、Vanessa Harawa、Rebecca E. Ruscoe、Anibal Cuetos、James D. Finnigan、Antonio Angelastro、Rachel S. Heath、Fabio Parmeggiani、Simon J. Charnock、Roger M. Howard、Rajesh Kumar、David S. B. Daniels、Gideon Grogan、Nicholas J. Turner
DOI:10.1038/s41586-022-04458-x
日期:2022.4.7
reductase (IRED) collection3 and originating from an unclassified Pseudomonas species, possesses an unusual active site architecture that facilitates amine-activated conjugate alkene reduction followed by reductiveamination. This enzyme can couple a broad selection of α,β-unsaturated carbonyls with amines for the efficient preparation of chiral amine diastereomers bearing up to three stereocentres. Mechanistic