Palladium-Catalyzed Alkyne Insertion/Reduction Route to Trisubstituted Olefins
作者:Erin R. Fruchey、Brendan M. Monks、Andrea M. Patterson、Silas P. Cook
DOI:10.1021/ol4018694
日期:2013.9.6
A new route to trisubstitutedolefins through a palladium-catalyzed alkyne insertion/reduction reaction with unactivated alkyl iodides is reported. The reaction proceeds under mild conditions and tolerates a range of functional groups and substitution patterns. Preliminary mechanistic inquiry suggests that the transformation may proceed through a hybrid radical/organometallic pathway.
An expedient visible-light-promoted atomtransferradicalcyclization (ATRC) reaction of unactivated alkyl iodides facilitated by earth-abundant and inexpensive manganese catalysis is described. The practical protocol shows a broad substrate scope and good functional-group tolerance, allowing for the preparation of synthetically valuable alkenyl iodides and diquinanes under simple and mild reaction
An efficient and facile method for the construction of tri- or tetrasubstituted exocyclic alkenes is achieved via a Cu(I)-catalytic system. This protocol exhibits mild conditions, low-cost catalyst, good functional group tolerance, and good yields. The selectivity toward tri- or tetrasubstituted alkenes can be delicately controlled by adjustment of base and solvent. A preliminary mechanism study manifested that the reaction undergoes a radical process, where B(2)pin(2) plays an indispensable role.