Preparation and stereoselective additions of highly substituted cyclic allylzinc reagents a zinc-ene cyclization
作者:Nicolas Millot、Paul Knochel
DOI:10.1016/s0040-4039(99)01689-5
日期:1999.10
Highly substituted cyclic allylzinc reagents 2 have been prepared by fragmentation of stericallyhindered homoallylic zinc alcoholates 1. Their reactions with aldehydes proceed under mild conditions and are highly stereoselective (64–86 %; Examples of acylation with benzonitrile and zinc-ene cyclization giving new spirobicyclic zinc reagents are also reported.
Hydrazone Radical Promoted Vicinal Difunctionalization of Alkenes and Trifunctionalization of Allyls: Synthesis of Pyrazolines and Tetrahydropyridazines
作者:Xiao-Yong Duan、Xiu-Long Yang、Ran Fang、Xie-Xue Peng、Wei Yu、Bing Han
DOI:10.1021/jo4016908
日期:2013.11.1
achieved by using TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) or DIAD (diisopropyl azodicarboxylate) as the hydrazone radical initiator as well as the carbon radical scavenger. Consequently, alkenes were difunctionalized to afford pyrazolines and tetrahydropyridazines via C–N forming 5-exo-trig and 6-exo-trig cyclizations, respectively, and allyls were trifunctionalized to afford pyrazolines via C–N forming
Carbocationic cyclizations initiated by dehalogenation of unsaturated α-bromoimine
作者:J.P. Bégué、D. Bonnet-Delpon、M. Charpentier-Morize、A. Richard
DOI:10.1016/s0040-4039(01)80918-7
日期:1985.1
Radical-Mediated Diamination of Alkenes with Phenylhydrazine and Azodicarboxylates: Highly Diastereoselective Synthesis of<i>trans</i>-Diamines from Cycloalkenes
作者:Ming-Kui Zhu、Yu-Chen Chen、Teck-Peng Loh
DOI:10.1002/chem.201203832
日期:2013.4.22
Metal‐free synthesis: Diamination of alkenes by using phenylhydrazine and azodicarboxylates could be achieved in a one‐pot manner under very mild conditions (see scheme; Boc=tert‐butoxycarbonyl). This process works with the assistance of acetic acid by means of a radical mechanism and displays a high trans selectivity when cycloalkene substrates were used in the reaction.