通过使用新的[(NHC)Ni(烯丙基)] BAr F催化剂(NHC = N杂环卡宾),首次使用环丙烯和炔烃作为底物对实现了交叉氢烯基化/重排级联反应(HARC )。通过控制(NHC)Ni II H与环丙烯和炔烃的相对插入反应性,可以高度选择性地获得宽范围的环戊二烯。新型(NHC)Ni II催化剂的结构特征对于反应成功至关重要。所采用的温和反应条件可以作为探索(NHC)Ni II辅助的乙烯基环丙烷重排反应性的入口。
[2+2] Cycloaddition of ketenes with ynamides. A general method for the synthesis of 3-aminocyclobutenone derivatives
作者:Amanda L. Kohnen、Xiao Yin Mak、Tin Yiu Lam、Joshua R. Dunetz、Rick L. Danheiser
DOI:10.1016/j.tet.2005.11.088
日期:2006.4
Ynamides react with ketenes in [2+2] cycloadditions leading to a variety of substituted 3-aminocyclobut-2-en-1-ones. The ynamides employed in these reactions are readily available via the copper-promoted N-alkynylation of carbamates and sulfonamides with alkynyl bromides and iodides. The scope of the [2+2] cycloaddition with regard to both the ketene and ynamide component is described.
Synthesis of Amides and Lactams in Supercritical Carbon Dioxide
作者:Xiao Yin Mak、Rocco P. Ciccolini、Julia M. Robinson、Jefferson W. Tester、Rick L. Danheiser
DOI:10.1021/jo9021875
日期:2009.12.18
ethoxy alkynes are performed at 120−130 °C, whereas tert-butoxy derivatives undergo the retro-ene reaction at 90 °C. With the exception of primary, unbranched amines, potential side reactions involving addition of the amines to carbon dioxide are not competitive with the desired C−N bond-forming reaction. The amide synthesis is applicable to the preparation of β-hydroxy and β-amino amide derivatives
Ynol Ethers as Ketene Equivalents in Rhodium-Catalyzed Intermolecular [5 + 2] Cycloaddition Reactions
作者:Paul A. Wender、Christian Ebner、Brandon D. Fennell、Fuyuhiko Inagaki、Birte Schröder
DOI:10.1021/acs.orglett.7b02765
日期:2017.11.3
electron-rich alkynes (ynol ethers) have been found to provide a highly efficient, direct route to dioxygenated seven-membered rings, a common feature of numerous natural and non-natural targets and building blocks for synthesis. The reactions proceed in high yield at roomtemperature and tolerate a broad range of functionalities. Substituted VCPs were found to react with high regioselectivity.
Phenylalanine enamide derivatives of formula (1) are described:
1
wherein
R
1
is a group Ar
1
L
2
Ar
2
Alk- in which:
Ar
1
is an optionally substituted aromatic or heteroaromatic group;
L
2
is a covalent bond or a linker atom or group;
Ar
2
is an optionally substituted arylene or heteroarylene group; and Alk is a chain —CH
2
—CH(R)13 , —CH═C(R)— or
2
in which
R is a carboxylic acid (—CO
2
H) or a derivative or biostere thereof;
X is an —O— or —S— atom or —N(R
2
)— group in which:
R
x
, R
y
and R
z
which may be the same or different is each a hydrogen atom or an optional substituent;
or R
z
is an atom or group as previously defined and R
x
and R
y
are joined together to form an optionally substituted spiro linked cycloaliphatic or heterocycloaliphatic group; and the salts, solvates, hydrates and N-oxides thereof.
The compounds are able to inhibit the binding of integrins to their ligands and are of use in the prophylaxis and treatment of immuno or inflammatory disorders or disorders involving the inappropriate growth or migration of cells.
Stereoselective Synthesis of Fully-Substituted Acrylonitriles via Formal Acylcyanation of Electron-Rich Alkynes
作者:Bing Liu、Yong Wang、Ying Chen、Qian Wu、Jing Zhao、Jianwei Sun
DOI:10.1021/acs.orglett.8b01180
日期:2018.6.15
A Sc(OTf)3-catalyzed formal acylcyanation of electron-rich alkynes for the efficient synthesis of fully-substituted acrylonitriles is described. By means of alkyne carbonyl metathesis, the reaction features mild conditions, high regio- and stereoselectivity, and a broad scope. The strong preference of the nitrile group for inward rotation in the torquoselective ring opening of the oxetane intermediate