Vasicine from Adhatoda vasica as an organocatalyst for metal-free Henry reaction and reductive heterocyclization of o-nitroacylbenzenes
作者:Sushila Sharma、Manoranjan Kumar、Vinod Bhatt、Onkar S. Nayal、Maheshwar S. Thakur、Neeraj Kumar、Bikram Singh、Upendra Sharma
DOI:10.1016/j.tetlet.2016.09.095
日期:2016.11
Vasicine, a quinazolinealkaloid, from the leaves of Adhatodavasica, has been utilized as an efficient catalyst for metal and base free Henry reaction of various aldehydes with nitro alkanes. The method can be used in the synthesis of various β-nitro alcohols under mild reaction conditions without use of hazardous organic solvents and expensive catalysts. Vasicine is also applied successfully for
Copper Complex of Aminoisoborneol Schiff Base Cu
<sub>2</sub>
(SBAIB‐d)
<sub>2</sub>
: An Efficient Catalyst for Direct Catalytic Asymmetric Nitroaldol (Henry) Reaction
new bifunctional coppercomplex of the aminoisoborneolSchiffbase – Cu2(SBAIB‐d)2 – has been developed for the effective directcatalyticasymmetricHenryreaction. One mol% of this catalyst produces the expected Henry products in high yields (up to 99%) with excellent enantioselectivities (up to 98% ee). The utility of the present catalyst was also extended to the Henryreaction with nitroethane
Merging Asymmetric Henry Reaction with Organocatalytic Cascade Reaction for the Construction of a Chiral Indolizidine Alkaloid Skeleton
作者:Yirong Zhou、Qin Yang、Jian Shen、Xin Chen、Yiyuan Peng、Yuefa Gong
DOI:10.1021/jo502379v
日期:2015.2.6
A sequential reaction combining the copper-catalyzed asymmetric Henry reaction with the organocatalytic Michael addition–hemiacetalization cascade reaction was developed. The C1-symmetric chiral diamine L1–copper complex was responsible for the first highly enantioselective Henry reaction, while diphenylprolinol silyl ether A acted as effective organocatalyst for the second cascade reaction between
Chiral binuclearcopper(II) Schiff base complexes 4a–g have been prepared from aldehydes 1a,b, (S)-amino alcohols 2a–f, and Cu(OAc)2·1H2O in high yield. Their catalysis is studied for the addition of nitroalkanes to aldehydes at ambient conditions with 76:24 er.