56572-27-1Relevant academic research and scientific papers
Rhodium-Catalyzed Oxidative Cycloaddition of N-tert-Butoxycarbonylhydrazones with Alkynes for the Synthesis of Functionalized Pyrroles via C(sp3)–H Bond Functionalization
Chan, Chun-Ming,Zhou, Zhongyuan,Yu, Wing-Yiu
supporting information, p. 4067 - 4074 (2016/12/30)
A rhodium(III)-catalyzed cycloaddition of N-tert-butoxycarbonylhydrazones with internal alkynes was developed. The reaction features a regioselective α-imino alkyl C(sp3)?H bond functionalization resulting in selective formation of highly functionalized NH-free pyrroles. Our studies showed that utilizing the N-tert-butoxycarbonyl (N-Boc) as the oxidizing directing group is critical for achieving the observed pyrrole formation versus the isoquinoline formation. To account for the pyrrole formation, we hypothesized that a prior tautomerization of the N-Boc-hydrazones to enamines should occur, followed by regioselective C(sp2)–H cleavage to form a putative five-membered rhodacycle. Subsequent coupling of the rhodacycle with the alkynes would afford the pyrrole products. (Figure presented.).
Catalytic enantioselective hydrogenation of N-alkoxycarbonyl hydrazones: A practical synthesis of chiral hydrazines
Yoshikawap, Naoki,Tan, Lushi,Christopher McWilliams,Ramasamy, Deepa,Sheppard, Ruth
supporting information; experimental part, p. 276 - 279 (2010/03/25)
(Figure presented) An enantioselective hydrogenation of hydrazones catalyzed by Rh complexes (Rh-Josiphos or Rh-Taniaphos) has been developed. The protocol can be applied to hydrazones with three different protective groups (Boc, Cbz, and methoxycarbonyl)
Stereoselective synthesis of cis- or trans-3,5-disubstituted pyrazolidines via pd-catalyzed carboamination reactions: Use of allylic strain to control product stereochemistry through N-substituent manipulation
Giampietro, Natalie C.,Wolfe, John P.
supporting information; experimental part, p. 12907 - 12911 (2009/03/12)
The stereoselective synthesis of either trans- or cis-3,5-disubstituted pyrazolidines is accomplished via Pd-catalyzed carboamination reactions of unsaturated hydrazine derivatives. The products are obtained in good yield with up to >20:1 diastereoselectivity. Stereocontrol is achieved by modulating the degree of allylic strain in the transition state for syn-aminopalladation through a simple modification of the substrate N2-substituent. The pyrazolidine products can be further transformed to 3,5-disubstituted pyrazolines via deprotection/oxidation, or to substituted 1,3-diamines via N-N bond cleavage.
