Photochemical Aminochlorination of Alkenes without the Use of an External Catalyst

Abstract

The niche field of photochemistry offers opportunities that are not found in “traditional” ground state chemical pathways. Aminochlorinated derivatives are an interesting family of 1,2‐difunctionalised compounds that provide access to a variety of natural products and pharmaceutical active substances. A practical, catalyst‐free chloroamination protocol is described herein, providing access to intermediates of great importance, utilising mild and photochemical reaction conditions (370 nm), where N‐chlorosulfonamides are used as both nitrogen and chlorine sources. A wide variety of olefins, decorated with a plethora of functional groups, was tested providing excellent results (28 examples, 18–88 % yield). Mechanistic studies (UV‐Vis, control experiments and quantum yield measurement) were also performed.

Regioselective Rearrangement of Nitrogen- and Carbon-Centered Radical Intermediates in the Hofmann–Löffler–Freytag Reaction

“…As in situ halogenation inhibits PBN’s ability to spin-trap radicals, the preparation of 7-Cl and 7-Br was performed in a separate step. While 7-Cl was easily isolated and proved stable for a couple of days, 50 7-Br had to be synthesized, cleaned, isolated, and measured without any delay. Another major point is the sensitivity of the reaction to air.…”

Blue Light-Induced 1,2-Aminochlorination of Olefins using Dichlorocarbamates

“…Using the method, a range of functionally diverse substrates are successfully aminochlorinated to yield the corresponding 1,2chloro-N-Cl compounds.Direct aminochlorination of olefins has gained a lot of attention in the recent years, with the development of a range of organocatalytic, photochemical and metal catalyzed methods. [1][2][3][4][5][6][7][8][9] Our interest in 1,2aminochlorinated compounds stems from their presence in recently isolated highly bioactive marine natural products, such as aaptocabamate F 4 and terpene alkaloid 5 (Scheme 1B). 10,11 When considering different entry points to access these alkaloids, we quickly focused on N,N-dichlorocarbamates.…”