124287-34-9Relevant articles and documents
Rhodium-Catalyzed B-H Bond Insertion Reactions of Unstabilized Diazo Compounds Generated in Situ from Tosylhydrazones
Pang, Yue,He, Qiao,Li, Zi-Qi,Yang, Ji-Min,Yu, Jin-Han,Zhu, Shou-Fei,Zhou, Qi-Lin
, p. 10663 - 10668 (2018)
Although transition-metal-catalyzed B-H bond insertion of carbenes into stable borane adducts has emerged as a promising method for organoborane synthesis, all the diazo compounds used to date as carbene precursors have had an electron-withdrawing group to stabilize them. Herein, we report a protocol for rhodium-catalyzed B-H bond insertion reactions of unstabilized diazo compounds generated in situ from tosylhydrazones. In addition, by using chiral dirhodium catalysts, we also achieved an asymmetric version of the reaction with good to excellent enantioselectivities (up to 98:2 e.r.). This is the first enantioselective heteroatom-hydrogen bond insertion reaction to use unstabilized diazo compounds as carbene precursors. The protocol exhibited good functional group tolerance and could be carried out on a gram scale. It also enabled one-pot transformation of a carbonyl group to a boryl group enantioselectively. The B-H bond insertion products could be easily transformed into chiral alcohols and other widely used organoboron reagents with enantiomeric fidelity.
Contributions to the Chemistry of Boron, 131. A New Ring System of Boron: 1,4-Dimethyl-1,4-dithionia-2,5-diboratacyclohexane
Noeth, Heinrich,Sedlak, Dieter
, p. 1479 - 1486 (2007/10/02)
(CH3)3N*BH2CH2SCH3 (3) was prepared via Li (2).It reacts with CH3I to yield the sulfonium salt I (4) and decomposes on heating to the title compound 8.The latter contains a six-membered ring in chair conformation and the methyl groups in equatorial positions as revealed by X-ray crystallography.