57238-66-1Relevant academic research and scientific papers
Tropylium-promoted carbonyl-olefin metathesis reactions
Tran, Uyen P.N.,Oss, Giulia,Pace, Domenic P.,Ho, Junming,Nguyen, Thanh V.
, p. 5145 - 5151 (2018/06/21)
The carbonyl-olefin metathesis (COM) reaction is a highly valuable chemical transformation in a broad range of applications. However, its scope is much less explored compared to analogous olefin-olefin metathesis reactions. Herein we demonstrate the use of tropylium ion as a new effective organic Lewis acid catalyst for both intramolecular and intermolecular COM and new ring-opening metathesis reactions. This represents a significant improvement in substrate scope from recently reported developments in this field.
GaCl3-Catalyzed Ring-Opening Carbonyl-Olefin Metathesis
Albright, Haley,Vonesh, Hannah L.,Becker, Marc R.,Alexander, Brandon W.,Ludwig, Jacob R.,Wiscons, Ren A.,Schindler, Corinna S.
supporting information, p. 4954 - 4958 (2018/08/24)
The development of a Lewis acid-catalyzed ring-opening cross-metathesis reaction which enables selective access to acyclic, unsaturated ketones as the carbonyl-olefin metathesis products is described. While catalytic amounts of FeCl3 were previously identified as optimal to catalyze ring-closing metathesis reactions, the complementary ring-opening metathesis between cyclic alkenes and carbonyl functionalities relies on GaCl3 as the superior Lewis acid catalyst.
Catalytic olefin hydroamination with aminium radical cations: A photoredox method for direct C-N bond formation
Musacchio, Andrew J.,Nguyen, Lucas Q.,Beard, G. Hudson,Knowles, Robert R.
supporting information, p. 12217 - 12220 (2014/12/09)
While olefin amination with aminium radical cations is a classical method for C-N bond formation, catalytic variants that utilize simple 2° amine precursors remain largely undeveloped. Herein we report a new visible-light photoredox protocol for the intramolecular anti-Markovnikov hydroamination of aryl olefins that proceeds through catalytically generated aminium radical intermediates. Mechanistic studies are consistent with a process involving amine oxidation via electron transfer, turnover-limiting C-N bond formation, and a second electron transfer step to reduce a carbon-centered radical, rendering the overall process redox-neutral. A range of structurally diverse N-aryl heterocycles can be prepared in good to excellent yields under conditions significantly milder than those required by conventional aminium-based protocols.
Intramolecular reactions of benzylic azides with ketones: Competition between Schmidt and Mannich pathways
Wrobleski,Aube
, p. 886 - 889 (2007/10/03)
The Lewis acid-promoted reactions of benzylic azides with ketones can proceed by two major pathways. The azido-Schmidt reaction involves simple addition of azide to the ketone followed by rearrangement and ring expansion. In addition, benzylic azides can undergo prior rearrangement to afford iminium ions that can subsequently participate in a Mannich reaction. A series of ketones containing an α CH2(CH2)nCH(N3)Ph substituent (n = 1-3) was prepared to investigate the dependence of products on ketone ring size and tether length. For all ketones examined, good yields of bicyclic lactams arising from intramolecular Schmidt reaction were obtained when a four-carbon linker was used (n = 1 in the above formulation), but Mannich products predominated for the longer tethers examined (n = 2, 3).
ALKYL-ALKENYL CROSS COUPLING VIA ALKYL COBALOXIME RADICAL CHEMISTRY. AN ALKYL EQUIVALENT TO THE HECK REACTION COMPATIBLE WITH COMMON ORGANIC FUNCTIONAL GROUPS
Branchaud, Bruce P.,Meier, Mark S.,Choi, Youngshin
, p. 167 - 170 (2007/10/02)
A novel cobalt-mediated radical-olefin coupling reaction is described which regenerates the olefin functionality in the final product.The regeneration of olefin functionality is unique among radical-olefin couplings using simple activated alkenes.
