The intermolecular hydroamination of unactivated alkenes with simple dialkyl amines remains an unsolved problem in organic synthesis. Here we report a catalytic protocol for efficient additions of cyclic and acyclic secondary alkyl amines to a wide range of alkyl olefins with complete anti-Markovnikov regioselectivity. In this process, C–N bond formation proceeds through a key aminium radical cation intermediate that is generated via electron transfer between an excited state iridium photocatalyst and an amine substrate. These reactions are redox neutral, completely atom economical, exhibit broad functional group tolerance, and occur readily at room temperature under visible light irradiation. Certain tertiary amine products are formally endergonic relative to their constituent olefin and amine starting materials and thus are not accessible via direct coupling with conventional ground state catalysts.

Aryl amination is an essential transformation for medicinal, process, and materials chemistry. In addition to classic Buchwald−Hartwig amination conditions, blue-light-driven metallaphotoredox catalysis has emerged as a valuable tool for C−N cross-coupling. However, blue light suffers from low penetration through reaction media, limiting its scalability for industrial purposes. In addition, blue light enhances unwanted side-product formation in metallaphotoredox catalysis, namely hydrodehalogenation. Low-energy light, such as deep red (DR) or near-infrared (NIR), offers a solution to this problem as it can provide enhanced penetration through reaction media as compared to higher-energy wavelengths. Herein, we show that lowenergy light can also enhance the desired reactivity in metallaphotoredox catalysis by suppressing unwanted hydrodehalogenation. We hypothesize that the reduced side product is formed by direct photolysis of the aryl−nickel bond by the high-energy light, leading to the generation of aryl radicals. Using deep-red or near-infrared light and an osmium photocatalyst, we demonstrate an enhanced scope of (hetero)aryl bromides and amine-based nucleophiles with minimal formation of hydrodehalogenation byproducts.

The development of a general catalytic system for the palladium-catalyzed carbocyclization of unactivated alkyl bromides with alkenes is described. This approach uses a commercially available bisphosphine ligand, and avoids the use of carbon monoxide atmosphere present in prior studies involving alkyl iodides. Detailed mechanistic studies of the transformation are performed, which are consistent with auto-tandem catalysis involving atom-transfer radical cyclization followed by catalytic dehydrohalogenation. These studies also suggest that reactions involving alkyl iodides may proceed through a metal-initiated, rather than metal-catalyzed, radical chain process.

. (2014). Synthesis of nitrogen-substituted methylenecyclopropanes by strain-driven overman rearrangement of cyclopropenylmethyl trichloroacetimidates. Journal of Organic Chemistry, 79 (17), 8462-8468. Synthesis of nitrogen-substituted methylenecyclopropanes by straindriven overman rearrangement of cyclopropenylmethyl trichloroacetimidates AbstractNitrogen-substituted methylenecyclopropanes have been prepared by a strain-driven Overman rearrangement of cyclopropenylmethyl trichloroacetimidates. The reaction proceeds at room temperature and without the need of a transition-metal catalyst. Furthermore, it has been shown that C-3-substituted cyclopropenylmethyl trichloroacetimidates undergo a hydrolytic ring-opening reaction to form allenylcarbinols. AbstractNitrogen-substituted methylenecyclopropanes have been prepared by a strain-driven

a b s t r a c tFlavonols are an important class of natural products isolated from plants. Some glycosylated flavonols showed very interesting biological activities. A library of flavonols has been made through Algar-Flynn-Oyamada reaction from 2 0 -hydroxyacetophenones and benzaldehydes. Glycosylation of these flavonols with various glycosyl donors affords a library of glycosylated flavonols. These compounds are potentially useful pharmacologically active compounds and will be studied for biological activities.