Regiospecific and highly stereoselective synthesis of β-amino (Z)-enylphosphonates via β-hydrogen migration reaction of dialkyl α-diazophosphonates catalyzed by AgOTf
to give β-amino (Z)-enylphosphonates in good yields with high regio- and stereoselectivity. A possible reaction mechanism shows that the steric effect could dramatically influence the geometric isomerism aptitude. This new method for constructing (Z)-β-amino vinylphosphonates should be of general utility in organic synthesis.
Unexpected Stereoselective Synthesis of (<i>Z</i>)-β-Alkenyl Substituted β-Amino Phosphonates through β,γ-Dihydrogen Shift Reaction Catalyzed by a Copper(I) Complex and Iodine [Cu(MeCN)<sub>4</sub>]PF<sub>6</sub>/I<sub>2</sub>
作者:Yan Cai、Hairong Lyu、Chengbin Yu、Zhiwei Miao
DOI:10.1002/adsc.201300838
日期:2014.2.10
AbstractA series of dialkyl α‐diazophosphonates has been prepared from natural amino acids. The diazo decomposition of these diazophosphonate compounds with tetrakis(acetonitrile)copper(I) hexafluorophosphate/iodine, [Cu(MeCN)4]PF6/I2, as catalyst has been investigated. It was found that the diazo decomposition of dialkyl α‐diazophosphonates gave a mixture of β,γ‐dihydrogen shift and 1,2‐hydride migration products and afforded β‐alkenyl‐substituted β‐amino phosphonates with the Z configuration. The mechanism of this novel diazo decomposition process was discussed.magnified image
1,2-Hydride Migration in Dialkyl α-Diazophosphonates Catalyzed by [Cu(MeCN)4]PF6: A Novel Approach to β-Amino (E)-Enylphosphonates
作者:Zhiwei Miao、Haihong Ge、Shuang Liu、Yan Cai、Yuchao Sun
DOI:10.1055/s-0035-1560373
日期:——
The regiospecific and stereoselective 1,2-migration reaction of dialkyl alpha-diazophosphonates for the synthesis of beta-amino (E)-enylphosphonates is developed utilizing tetrakis(acetonitrile)copper(I) hexafluorophosphate [Cu(MeCN)(4)PF6] as the catalyst and N,N-dimethylformamide as an additive. A possible mechanism for the 1,2-migration reaction involving a metal carbene is presented. An investigation on the E/Z isomer selectivity of this process demonstrates that steric factors play an important role on the outcome. This process provides a straightforward access to beta-amino (E)-enylphosphonates in moderate to good yields.