Efficient Synthesis of 2-Ureaguanines via the in situ Reactions of 2-Isocyanatopurines with Amines
摘要:
The synthesis of 2-ureaguanines is reported. The preparation involves a suitably protected intermediate, formation of a 2-isocyanatopurine and in situ trapping with a diverse range of amines followed by double deprotection. This is the first application of 2-isocyanatopurines for the synthesis of 2-ureaguanines.
C−H Methylation of Iminoamido Heterocycles with Sulfur Ylides**
作者:Prithwish Ghosh、Na Yeon Kwon、Saegun Kim、Sangil Han、Suk Hun Lee、Won An、Neeraj Kumar Mishra、Soo Bong Han、In Su Kim
DOI:10.1002/anie.202010958
日期:2021.1.4
The direct methylation of N‐heterocycles is an important transformation for the advancement of pharmaceuticals, agrochemicals, functional materials, and other chemical entities. Herein, the unprecedented C(sp2)‐H methylation of iminoamido heterocycles as nucleoside base analogues is described. Notably, trimethylsulfoxonium salt was employed as a methylating agent under aqueous conditions. A wide substrate
Preparation and reactivity of α-phenylselenenyl ethers
作者:David J. Goldsmith、Dennis C. Liotta、Mark Volmer、William Hoekstra、Liladhar Waykole
DOI:10.1016/s0040-4020(01)96726-2
日期:1985.1
α-Phenylsclenenyl cyclic ethers may be prepared by the reactions of either lactols or lactol acetates with benzeneselenol, or from lactones by the “one-pot” process of reduction and Lewis acid catalyzed selenation. The tetrahydropyranyl phenyl selenides also exhibit a significant anomeric effect and its size has been estimated. The selenenyl ethers are converted to enol ethers through an oxidative elimination
Cyanotrimethylsilane adds to some ⇌,β-unsaturated ketones in conjugate manner under the catalytic action of Lewis acids such as triethylaluminium, aluminiumchloride, and SnCl2. Hydrolysis of the products gives β-cyano ketones which are identical to the hydrocyanated products of the starting enones. The title silicon reagent reacts with acetals and orthoesters under the catalytic action of SnCI2 or BF3-OEt2
TETRAHYDROPYRANYL LOWER ALKYL ESTERS AND THE PRODUCTION OF SAME USING A KETENE COMPOUND
申请人:BASF SE
公开号:US20200325112A1
公开(公告)日:2020-10-15
The present invention relates to tetrahydropyranyl lower akyl esters and specifically to tetrahydropyranyl acetates, a method for preparation thereof using ketene and use thereof as fragrances and aroma substances.
Lewis Acid Promoted Mukaiyama Aldol-Prins (MAP) Cyclizations of Acetals, Ketals, α-Acetoxy Ethers, and Orthoformates
作者:Scott Rychnovsky、Michael Gesinski、Lori Van Orden
DOI:10.1055/s-2008-1032053
日期:2008.2
The Mukaiyama aldol-Prins (MAP) cyclization of acetals stereoselectively provided substituted tetrahydropyrans. The scope of the reaction has been expanded to include other electrophiles, including ketals and α-acetoxy ethers. Finally, a double MAP cyclization with orthoformates is described.