Tandem Blaise/retro-Blaise Reaction for the Nitrile-Mediated Regioselective Intermolecular Addition of Unstabilized Zinc Ester Enolates (Reformatsky Reagents) to 1-Alkynes and 1,3-Enynes
作者:Ju Hyun Kim、Yu Sung Chun、Sang-gi Lee
DOI:10.1021/jo402015n
日期:2013.11.15
of a nitrile as a mediator to achieve the regioselective intermolecular addition of unstabilized zinc ester enolates (Reformatskyreagents) to 1-alkynes and 1,3-enynes. This reaction is made possible by a reversible addition of enolates to a nitrile (Blaise reaction), generating a zinc aza-enolate that, unlike zinc ester enolates, can add intermolecularly to 1-alkynes and 1,3-enynes. Subsequent removal
Palladium-Catalyzed Highly Regio- and Stereoselective Addition of Organoboronic Acids to Allenes in the Presence of AcOH
作者:Shengming Ma、Ning Jiao、Longwu Ye
DOI:10.1002/chem.200305301
日期:2003.12.15
The Pd(0)-catalyzedregio- and stereoselective addition of organoboronicacids to allenes leads to stereodefined tri- or tetrasubstituted alkenes. Furthermore, this method shows high substitutent-loading capability and tolerance of various substitutents. A hydropalladation-Suzuki coupling mechanism, which may account for the regio- and stereoselectivity, is proposed.
Iron-catalyzed stereospecific arylation of enol tosylates using Grignard reagents
作者:Yi-Ming Wei、Xiao-Di Ma、Lei Wang、Xin-Fang Duan
DOI:10.1039/c9cc09522e
日期:——
The stereospecific Fe-catalyzed arylation of enol tosylates was reported. Various tri- or tetrasubstituted Z or E-enol tosylates of β-keto esters were arylated using common and Knochel-type Grignard reagents with complete stereofidelity. The precursors for Z/E-zimelidine, tamoxifen and other bioactive compounds were facilely prepared without precious and toxic transition metals.
The present invention provides an aryl sulfamate derivative represented by Formula (I)
1
(wherein R
r
and R
s
, which may be the same or different, each represent a hydrogen atom or lower alkyl R
1
, R
2
, R
3
and R
4
, which may be the same or different, each represent a hydrogen atom, lower alkyl, a halogen atom, nitro, cyano, azido, or the like, R
5
represents a hydrogen atom, substituted or unsubstituted alkyl, substituted or unsubstituted lower cycloalkyl, or the like, R
6
represents a hydrogen atom, substituted or unsubstituted alkyl, a halogen atom, or the like, or R
5
and R
6
are joined to form a bond, and R
7
represents X
1
NR
23
R
24
or COR
26
), or a pharmaceutically acceptable salt thereof.