Reaction of phenylcarbene formed from benzaldehyde tosylhydrazone in certain solvents
作者:H. Nozaki、R. Noyori、K. Sisido
DOI:10.1016/s0040-4020(01)98979-3
日期:1964.1
tosylhydrazone (I) with sodium methoxide in various solvents under irradiation and/or heating yields products arising fromphenylcarbene (IV) which is produced by photolytic or pyrolytic decomposition of initially formed phenyldiazomethane (III). Reaction products originating solely from the tosylhydrazone (I) are (VI ∼ XI) while those produced by the interaction with solvents are formulated as addition
Catalytic Asymmetric Epoxidation of Aldehydes. Optimization, Mechanism, and Discovery of Stereoelectronic Control Involving a Combination of Anomeric and Cieplak Effects in Sulfur Ylide Epoxidations with Chiral 1,3-Oxathianes
作者:Varinder K. Aggarwal、J. Gair Ford、Sílvia Fonquerna、Harry Adams、Ray V. H. Jones、Robin Fieldhouse
DOI:10.1021/ja9812150
日期:1998.8.1
A range of 1,3-oxathianes based on camphorsulfonic acid have been prepared and tested in the catalytic asymmetricepoxidation of carbonyl compounds. It was found that the 1,3-oxathiane derived from acetaldehyde 5b gave the highest yield and enantioselectivity in the epoxidation process. The enantioselectivity was independent of the solvent and metal catalyst used (although yields were dependent on
Alkylation of Aldehyde (Arenesulfonyl)hydrazones with Trialkylboranes
作者:George W. Kabalka、John T. Maddox、Ekaterini Bogas、Shane W. Kelley
DOI:10.1021/jo962089q
日期:1997.5.1
(Arenesulfonyl)hydrazone derivatives of aryl aldehydes are readily alkylated by trialkylboranes in the presence of base to generate new organoboranes that may be converted to the corresponding substituted alkanes or alcohols depending upon the reaction conditions chosen. Both tosyl- and trisylhydrazone derivatives can be utilized in the reaction, which tolerates a variety of functional groups, making it a versatile alternative to both the Grignard and Suzuki-coupling reactions.
A new example of C=N double bonds formation in metal carbene insertion reactions is reported. Remarkably, the general 1,2-migration process of the corresponding ylide intermediates in X-H carbene insertion reactions...
Palladium/GF-Phos-catalyzed asymmetric carbenylative amination to access chiral pyrrolidines and piperidines
作者:Yue Sun、Chun Ma、Zhiming Li、Junliang Zhang
DOI:10.1039/d2sc03999k
日期:——
but the development of catalyticenantioselective versions still poses considerable challenges and only very limited examples have been reported. We herein report an asymmetric palladium/GF-Phos-catalyzed carbenylative amination reaction of N-tosylhydrazones and (E)-vinyl iodides pendent with amine, which allows facile access to a range of chiral pyrrolidines and piperidines in good yields (45–93%)
N-甲苯磺酰腙的交叉偶联已成为构建结构多样化分子的有效方法,但催化对映选择性版本的开发仍然面临相当大的挑战,并且仅报道了非常有限的例子。我们在此报告了一种不对称钯/GF-Phos催化的N-甲苯磺酰腙和( E )-乙烯基碘化物与胺悬垂的羧基胺化反应,该反应可以轻松获得一系列手性吡咯烷和哌啶,产率良好(45-93%) ) 高达 96.5: 3.5 er 。此外,条件温和、底物范围广泛、制备规模化以及天然产物(−)-norruspoline的高效合成是该方法的实用特点。