The zinc–mediated aqueous Barbier–Grignardreaction of cyclic allylic bromide substrates with various aldehydes and ketones to afford homoallylic alcohols was investigated. Aromatic aldehydes and ketones afforded adducts in good yields (66–90%) and with good diastereoselectivities. Non–aromatic aldehydes also reacted well under these conditions, but only poor yields were obtained with non–aromatic
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.