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
Reductive heterocyclizations via indium/iodine-promoted one-pot conversion of 2-nitroaryl aldehydes, ketones, and imines
作者:Rongbi Han、Kee In Son、Gil Hwan Ahn、Young Moo Jun、Byung Min Lee、Younbong Park、Byeong Hyo Kim
DOI:10.1016/j.tetlet.2006.08.027
日期:2006.10
2-Nitroaryl aldehydes, ketones, and imines were reductively cyclized to 2,1-benzisoxazoles with good yields in the presence of indium and iodine in MeOH. Under a similar condition, N-(2-nitrobenzylidene)anilines were produced mixtures of 2,1-benzisoxazoles and 3-anilino-2-phenyl-2H-indazoles.
Reductive heterocyclizations via indium–iodine-promoted conversion of 2-nitroaryl imines or 2-nitroarenes to 2,3-diaryl-substituted indazoles
作者:Gil Hwan Ahn、Jung June Lee、Young Moo Jun、Byung Min Lee、Byeong Hyo Kim
DOI:10.1039/b707240f
日期:——
N-(2-nitrobenzylidene)anilines produced mixtures of 2,1-benzisoxazoles and 3-anilino-2-aryl-2H-indazoles in the presence of indium and iodine in MeOH, N-(2-nitrobenzylidene)anilines were transformed into 3-anilino-2-aryl-2H-indazoles as the predominant major product through the change of the solvent from protic MeOH to aprotic THF. In an indium-mediated one-pot reductive reaction, 2-benzaldehydes and anilines in THF
Gold-Catalyzed Synthesis of Quinolines from Propargyl Silyl Ethers and Anthranils through the Umpolung of a Gold Carbene Carbon
作者:Hongming Jin、Bin Tian、Xinlong Song、Jin Xie、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/anie.201606043
日期:2016.10.4
proceeds through a sequential ring opening/1,2‐H‐shift/protodeauration/Mukaiyama aldol cyclization. This method offers a regiospecific and modular access to 2‐aminoquinolines and other quinoline derivatives under mild conditions and with a broad functional‐group tolerance. The conversion is possible on a gram scale, which underlines the synthetic practicability of this methodology. The versatility of the
Gold‐Catalyzed Reaction of Anthranils with Alkynyl Sulfones for the Regioselective Formation of 3‐Hydroxyquinolines
作者:Yufeng Wu、Chao Hu、Tao Wang、Lukas Eberle、A. Stephen K. Hashmi
DOI:10.1002/adsc.202101469
日期:2022.3.30
the epoxide intermediate stems from the thermodynamic stability difference of the resultant cation according to quantum chemical calculations. The subsequent semi-pinacol rearrangement leads to the 1,2-shift of an aryl or alkyl group originating from the sulfone. A gram-scale synthesis of 3-hydroxyquinoline further manifests the viability of the protocol for the preparation of this important scaffold