Practical and stereoselective electrocatalytic 1,2-diamination of alkenes

Abstract

The 1,2-diamine motif is widely present in natural products, pharmaceutical compounds, and catalysts used in asymmetric synthesis. The simultaneous introduction of two amino groups across an alkene feedstock is an appealing yet challenging approach for the synthesis of 1,2-diamines, primarily due to the inhibitory effect of the diamine products to transition metal catalysts and the difficulty in controlling reaction diastereoselectivity and regioselectivity. Herein we report a scalable electrocatalytic 1,2-diamination reaction that can be used to convert stable, easily available aryl alkenes and sulfamides to 1,2-diamines with excellent diastereoselectivity. Monosubstituted sulfamides react in a regioselective manner to afford 1,2-diamines bearing different substituents on the two amino groups. The combination of an organic redox catalyst and electricity not only obviates the use of any transition metal catalyst and oxidizing reagent, but also ensures broad reaction compatibility with a variety of electronically and sterically diverse substrates.

Enantiospecific electrochemical rearrangement for the synthesis of hindered triazolopyridinone derivatives

“…The substrates with a naphthyl, thienyl, or allylic substituent were also effective, albeit in lower yields (22)(23)(24). Next, the secondary alkyl carboxylic acids were tested (25)(26)(27)(28)(29)(30)(31)(32)(33)(34). The substrates with either alkyl or phenyl substituents at the benzyl position all gave the corresponding products in excellent yields (25)(26)(27)(28)(29).…”

“…The substrates with either alkyl or phenyl substituents at the benzyl position all gave the corresponding products in excellent yields (25)(26)(27)(28)(29). Substrates with a heteroatom at the α-C were also effective although the yields dropped, probably because of the inductive effect of the heteroatom (30)(31)(32)(33)(34). The tertiary carboxylic acids such as simple alkyl substituted (35)(36)(37), deuterated (38), fluorinated (39), and cyclic systems (41)(42)(43)(44) were demonstrated effective as well.…”

“…However, the atom economy of Barton type decarboxylation is low because of the requirement of activating groups, which were discarded as waste after the reaction. Very recently, Baran et al reported an elegant synthesis of hindered dialkyl ethers with electrogenerated carbocations generated from alkyl carboxylic acids 23 , which demonstrates the power of electrochemistry to substantially improve the synthetic efficiency [24][25][26][27][28][29][30][31][32][33][34] . Rearrangement reactions through a molecular skeletal reorganization are powerful chemical transformations for generating structural complexity and diversity [35][36][37][38][39] .…”

Distinctive reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under photoredox conditions

“…Notably, 1,2-diamines have widespread applications as core structures in a variety of natural products, pharmaceuticals, and agrochemicals [34][35][36][37][38] and are valuable ligands [39,40] in stereoselective organic synthesis. Despite the availability of a plethora of synthetic methods for 1,2-diamines [41][42][43][44][45], the reported photocatalytic synthetic methods are mainly limited to aniline-based substrates and do not encompass aliphatic amines. We planned the synthesis of 1,2-diamine compounds having an aliphatic amine moiety by the intermolecular coupling of N-benzylidines with aliphatic amines that not only act as coupling partner but also as electron donors in the photoredox cycle, and the results are reported herein.…”

Distinctive Reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under Photoredox Catalysis

“…in stereoselective organic synthesis. Despite the availability of a plethora of synthetic methods for 1,2-diamines,[41][42][43][44][45] the reported photocatalytic synthetic methods are mainly limited to aniline-based substrates and do not encompass aliphatic amines.Scheme 1: Photocatalytic transformations of imines.We planned the synthesis 1,2-diamine compounds having aliphatic amine moiety by intermolecular coupling of N-benzylidines with aliphatic amines which not only act as coupling partner but also as electron donor in photoredox cycle, the results of which we report herein. We began with the reaction of the simple N-benzylideneaniline.However, this substrate did not furnish the desired products under several different…”