Theoretical calculations of the [2,3]-sila-wittig rearrangement of isomers of [(allyloxy)silyl]lithium (C3H5O)HzSiLi have been performed in the gas phase and THF solvent using the G3MP2B3 method. Seven isomers of ...Theoretical calculations of the [2,3]-sila-wittig rearrangement of isomers of [(allyloxy)silyl]lithium (C3H5O)HzSiLi have been performed in the gas phase and THF solvent using the G3MP2B3 method. Seven isomers of silylenoid (C3H5O)H2SiLi, 1-7, are found. The [2,3]-silawittig rearrangement paths are followed using two isomers, 2 and 4, to yield the transition states as well as the products. In the transition state, the silicon center functions as a nucleophile and the aUyl as an electrophile. The interaction between the silicon and allylic sites leads to the formation of SiC(3) bond and the break of O-C(1) bond. Finally, the (allylsilyl)oxylithium (C3H5)H2SiOLi is obtained. The rearrangement paths are confirmed by the intrinsic reaction coordinate (IRC) calculations. The rearrangement mechanisms of reactions of 2 and 4 are similar, and the latter reaction is more favored in the gas phase and THF solvent. Also, the solvent effects are analyzed in this work.展开更多
基金PhD Special Research Foundation of Chinese Education Department (No. 20040422010)the Scientific Research Foundation of Yangzhou University
文摘Theoretical calculations of the [2,3]-sila-wittig rearrangement of isomers of [(allyloxy)silyl]lithium (C3H5O)HzSiLi have been performed in the gas phase and THF solvent using the G3MP2B3 method. Seven isomers of silylenoid (C3H5O)H2SiLi, 1-7, are found. The [2,3]-silawittig rearrangement paths are followed using two isomers, 2 and 4, to yield the transition states as well as the products. In the transition state, the silicon center functions as a nucleophile and the aUyl as an electrophile. The interaction between the silicon and allylic sites leads to the formation of SiC(3) bond and the break of O-C(1) bond. Finally, the (allylsilyl)oxylithium (C3H5)H2SiOLi is obtained. The rearrangement paths are confirmed by the intrinsic reaction coordinate (IRC) calculations. The rearrangement mechanisms of reactions of 2 and 4 are similar, and the latter reaction is more favored in the gas phase and THF solvent. Also, the solvent effects are analyzed in this work.
基金The authors are grateful for the financial supports from the Natural Science Foundation of Hunan Province,China(2019JJ50797)the Postdoctoral Science Foundation of China(2019T120711).