1162672-72-1Relevant academic research and scientific papers
Selectivity control in alkylidene carbene-mediated C-H insertion and allene formation
Zheng, Jun-Cheng,Yun, Sang Young,Sun, Chunrui,Lee, Nam-Kyu,Lee, Daesung
, p. 1086 - 1099 (2011)
Regioselectivity of alkylidene carbene-mediated C-H insertion was explored utilizing electronic, conformational, steric, and stereoelectronic effects. Relying on these factors, highly regio-and chemoselective carbene insertion reaction of C-H bonds in different environments could be obtained. The observed selectivity clearly indicates that an electronic effect plays a more important role than steric effect. In general, C-H bonds in conformationally rigid cyclic environments are less reactive than those in acyclic systems toward carbene insertion, and in this situation, a competing intermolecular reaction between alkylidene carbene and trimethylsilyldiazomethane led to the formation of allenylsilanes. The formation of allenylsilane becomes more favorable as the concentration of reaction becomes higher, as well as the C-H bonds undergoing insertion becomes electronically and conformationally deactivated.
Stereoelectronic effect for the selectivity in C-H insertion of alkylidene carbenes and its application to the synthesis of platensimycin
Sang, Young Yun,Zheng, Jun-Cheng,Lee, Daesung
supporting information; experimental part, p. 8413 - 8415 (2009/10/23)
(Figure Presented) A systematic study of C-H insertion reactions with variously substituted and conformationally constrained substrates was carried out. High selectivity in the insertion between two competing C-H bonds caused by a strong stereoelectronic effect of an oxygen substituent was achieved. This regioselective C-H insertion reaction was employed as a platform to develop a concise asymmetric synthesis of platensimycin.
