We report the synthesis of derivatives of vitamin K3 as well as of vitaminsK1 and K2 containing a different number of methyl groups in various positions in order to reduce their redox potentials and to change systematically their steric features. The long aliphatic chain of vitaminsK1 and K2 is simulated by an undecyl chain or a methyl group, respectively. The redox potentials of the first reduction
Enantioselective Functionalization of Inactive sp<sup>3</sup> C–H Bonds Remote to Functional Group by Metal/Organo Cooperative Catalysis
作者:Xiao-Le Zhou、Pu-Sheng Wang、Da-Wei Zhang、Peng Liu、Cheng-Ming Wang、Liu-Zhu Gong
DOI:10.1021/acs.orglett.5b02653
日期:2015.10.16
A metal/organo cooperative catalysis to enable the enantioselective functionalization of inactive C-H bonds gamma to the formyl group in aliphatic aldehydes has been established. Instead of using enals as substrates in traditional organocatalytic cydization reactions, the aliphatic aldehydes directly participated in [4 + 2] cyclization with quinone derivatives exploiting molecular oxygen as oxidants to afford optically active cyclic molecules with excellent levels of enantioselectivity. This method features a combination of pot, step, and atom economy.
Farina, F.; Fernandez, E.; Gimeno, V., Anales de Quimica, 1995, vol. 91, # 3-4, p. 220 - 229
作者:Farina, F.、Fernandez, E.、Gimeno, V.、Valderrama, J. A.