Enantioselective Bromocyclization of Allylic Amides Catalyzed by BINAP Derivatives
摘要:
A highly enantioselective bromocyclization of allylic amides with N-bromosuccinimide (NBS) was developed with DTBM-BINAP as a catalyst, affording chiral oxazolines with a tetrasubstituted carbon center in high yield with up to 99% ee. By utilizing the bromo substituent as a handle, the obtained compounds were converted to synthetically useful chiral building blocks.
Visible-light-promoted radical alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester: Synthesis of oxazolines
作者:Zhiyang Yan、Bin Sun、Panyi Huang、Haiyun Zhao、Hao Ding、Weike Su、Can Jin
DOI:10.1016/j.cclet.2021.09.067
日期:2022.4
An efficient photocatalytic alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester has been developed. The transformation is taken advantage of alkyl radicals to attack allylic amide with the assist of inexpensive rose bengal as photocatalyst to prepare a series of alkyl substituted oxazolines in moderate to excellent yields. High regioselectivity, operational safety, mild conditions
Solvent-Dependent Enantiodivergence in the Chlorocyclization of Unsaturated Carbamates
作者:Atefeh Garzan、Arvind Jaganathan、Nastaran Salehi Marzijarani、Roozbeh Yousefi、Daniel C. Whitehead、James E. Jackson、Babak Borhan
DOI:10.1002/chem.201300189
日期:2013.7.1
A remarkable solvent‐controlled enantiodivergence is seen in the hydroquinidine 1,4‐phthalazinediyl diether ((DHQD)2PHAL)‐catalyzed chlorocyclization of unsaturatedcarbamates. Eyring plot analyses of this previously unreported reaction are used to probe and compare the R‐ and S‐selective pathways. In the CHCl3/hexanes solvent system, the pro‐R process shows a surprising increase in selectivity with
Catalytic asymmetric CO<sub>2</sub> utilization reaction for the enantioselective synthesis of chiral 2-oxazolidinones
作者:Ryuichi Nishiyori、Taiki Mori、Seiji Shirakawa
DOI:10.1039/d3ob00555k
日期:——
asymmetric bromocyclizations of in situgenerated carbamic acids from CO2 and allylamines were achieved via the use of a BINOL-derived chiral bifunctional selenide catalyst bearing a hydroxy group. Chiral 2-oxazolidinone products as important pharmaceutical building blocks were obtained with good enantioselectivities by the present catalytic asymmetric CO2 utilization reactions.
通过使用带有羟基的 BINOL 衍生的手性双功能硒化物催化剂,实现了由 CO 2和烯丙胺原位生成的氨基甲酸的催化不对称溴化环化。通过本催化不对称CO 2利用反应获得了具有良好对映选择性的手性2-恶唑烷酮产物作为重要的药物结构单元。
Characterization of a Series of 3-Amino-2-phenylpropene Derivatives as Novel Bovine Chromaffin Vesicular Monoamine Transporter Inhibitors
作者:Rohan P. Perera、D. Shyamali Wimalasena、Kandatege Wimalasena
DOI:10.1021/jm030004p
日期:2003.6.1
A series of 3-amino-2-phenylpropene (APP) derivatives have been synthesized and characterized as novel competitive inhibitors, with K-i values in the muM range, for the bovine chromaffin granule membrane monoamine transporter(s) (bVMAT). Although, these inhibitors are structurally similar to the bVMAT substrate tyramine, none of them were measurably transported into the granule. Structure-activity studies have revealed that, while the 3'- or 4'-OH groups on the aromatic ring enhance the inhibition potency, Me or OMe groups in these positions reduce the inhibition potency. Halogen substitution on the 4'-position of the aromatic ring causes gradual increase of the inhibition potency parallel to the electron donor ability of the halogen. Substituents on the NH2 as well as on the 3-position of the alkyl chain reduce the inhibition potency. Comparative structure-activity analyses of APP derivatives with tyramine and the neurotoxin 1-methyl-4-phenylpyridinium suggest that the flexibility of the side chain and the relative orientation of the NH2 group may be critical for the efficient transport of the substrate through the bVMAT. Comparable bVMAT affinities of these inhibitors to that of DA and other pharmacologically active amines suggest that they are suitable for the structure-activity and mechanistic studies of monoamine transporters and may also be useful in modeling the mechanism of action of amphetamine-related derivatives.
Stabase-protected 2-chloroallylamine: a useful synthon for primary allylic amines via nickel-catalyzed cross-coupling
作者:Thomas M. Bargar、Jefferson R. McCowan、James R. McCarthy、Eugene R. Wagner