Practical approaches to labelling terminal alkynes with deuterium
作者:Melanie Y. T. Chan、Arbab Anwar、William J. S. Lockley
DOI:10.1002/jlcr.3963
日期:2022.4
Base catalysed exchange with sodium hydroxide, calcium oxide or N,N,N,N-tetramethylguanidine in deuterium oxide is a viable procedure for the preparation of terminally deuterated alkynes for those alkynes stable to strong base. The use of silver perchlorate as a catalyst is an alternative practical option when labelling alkynes which are sensitive to base or contain functionalities which would lead to labelling elsewhere in the molecule. Labelling with this catalyst takes place smoothly at ambient temperature in a mixture of N,N-dimethylformamide and deuterium oxide.
Divergent Elementoboration: 1,3‐Haloboration versus 1,1‐Carboboration of Propargyl Esters
作者:Lewis C. Wilkins、Yashar Soltani、James R. Lawson、Ben Slater、Rebecca L. Melen
DOI:10.1002/chem.201801493
日期:2018.5.23
This work showcases the 1,3‐haloboration reaction of alkynes in which boron and chlorine add to propargyl systems in a proposed sequential oxazoliumborate formation with subsequent ring‐opening and chloride migration. In addition, the functionalization of these propargyl esters with dimethyl groups in the propargylic position leads to stark differences in reactivity whereby a formal 1,1‐carboboration