1. Department of Chemistry Tsinghua University Beijing 100084 P. R. China
2. Department of Materials Science and Engineering China University of Petroleum (East China) Qingdao 266580 P. R. China
3. Biobased Chemistry and Technology Wageningen University Bornse Weilanden 9 6708WG Wageningen The Netherlands
4. Laboratory of Organic Chemistry Wageningen University Stippeneng 4 6708WE Wageningen The Netherlands
5. Department of Chemical Engineering and Technology Xi'an Jiaotong University Xi'an 710049 P. R. China