71732-80-4Relevant articles and documents
Organolanthanide-catalyzed hydroamination/cyclization. Efficient allene- based transformations for the syntheses of naturally occurring alkaloids
Arredondo, Victor M.,Tian, Shun,McDonald, Frank E.,Marks, Tobin J.
, p. 3633 - 3639 (1999)
The total syntheses of the pyrrolidine alkaloid (+)-197B (1) and pyrrolizidine alkaloid (+)-xenovenine (2) are described. The strategy involves enantioselective syntheses of the aminoallene, (5S,8S)-5-amino- trideca-8,9-diene (3), and the aminoallene-alkene, (5S)-5-amino-pentadeca- 1,8,9-triene (4), which then undergo regio- and stereoselective cyclohydroamination catalyzed by the organolanthanide precatalysts Cp'2LnCH(TMS)2 and Me2SiCp''((t)BuN)LnN(TMS)2 (Cp' = η5-Me5C5; Cp'' = η5-Me4C5; Ln = lanthanide; TMS = Me3Si). These reactive organolanthanide complexes efficiently mediate highly diastereoselective intramolecular hydroamination/cyclization (IHC) reactions under mild conditions. The turnover-limiting step in these catalytic cycles is proposed to be intramolecular insertion into the Ln-N bond of the proximal allenic C=C linkage, followed by rapid protonolytic cleavage of the resulting Ln-C bond. The rate and selectivity of the insertion process is highly sensitive to the steric demands of the substrate.
Redox-Triggered α-C-H Functionalization of Pyrrolidines: Synthesis of Unsymmetrically 2,5-Disubstituted Pyrrolidines
Cheng, Yong-Feng,Rong, Hao-Jie,Yi, Cheng-Bo,Yao, Jun-Jun,Qu, Jin
, p. 4758 - 4761 (2015/10/12)
By using o-benzoquinone as an internal oxidant, the regio- and diastereoselective functionalization of the secondary over the tertiary α-C-H bond of 2-substituted pyrrolidines is first realized. Subsequent intermolecular addition of a nucleophile to the g
Efficient carboazidation of alkenes using a radical desulfonylative azide transfer process
Weidner, Karin,Giroult, Andre,Panchaud, Philippe,Renaud, Philippe
supporting information; experimental part, p. 17511 - 17515 (2011/02/23)
The radical-mediated carboazidation of terminal alkenes using electrophilic alkanesulfonyl azides is reported. A single reagent delivers the necessary electrophilic alkyl radical as well as the azido group, and good yields are obtained by using a moderate excess of the carboazidating reagent (1.5-2 equiv). Interestingly, in addition to the starting sulfonyl azide, this method requires only the use of a radical initiator, di-tert-butyldiazene. In terms of atom economy, this azide transfer reaction is close to ideal, as SO2 (1 equiv) is the only side product. The synthetic potential of this process has been demonstrated by a formal synthesis of the alkaloid lepadiformine C.