Synthesis of Differentially Substituted 1,2-Diamines through Advances in C–H Amination Technology

Abstract

A general, high yielding method for the synthesis of 1,2-diamine derivatives is described that capitalizes on selective, rhodium-catalyzed C-H insertion of hydroxylamine-based sulfamate esters. The resulting Troc-protected oxathiadiazinane heterocycles are easily modified and can be reduced under the mild action of NaI to afford differentially substituted diamine products. This technology offers a number of salient improvements over related C-H and π-bond amination tactics for diamine synthesis.

Stereoselective C  N Bond‐Forming Reactions Through C ( sp 3 ) H Bond Insertion of Metal Nitren

“…Complex 8, thus, has enabled to extend the scope of the intramolecular C(sp 3 )-H amination reaction that can be performed with catalyst loading as low as 1 mol% starting from ureas and guanidines, [56] sulfamides, [57] and O-(sulfamoyl)-hydroxylamines. [58] More importantly, the Rh2(esp)2 complex 8 has led to the development of efficient conditions for the intermolecular C(sp 3 )-H amination reaction. Good conversions were often achieved only in the presence of an excess of substrate because of the high reactivity of the metallanitrene species.…”

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

“…However, the scope of catalytic C(sp 3 )–H amination and alkene aziridination reactions has been greatly enhanced following the discovery of practical procedures for the in situ generation of iminoiodinanes, a synthesis which is known to be troublesome [ 91 – 93 ]. According to these protocols and following the design of dirhodium(II) complexes, highly efficient catalytic nitrene transfers have been reported from carbamates [ 92 ], sulfamates [ 94 – 97 ], ureas and guanidines [ 98 ], sulfamides [ 99 ], hydroxylamine-derived sulfamates [ 100 ], carbamimidates [ 101 ], and sulfonimidamides [ 102 – 107 ]. These reactions involve the formation of a metal-bound nitrene that can insert into a C(sp 3 )–H bond or a π-bond via the asynchronous concerted addition of a singlet species or a stepwise radical pathway ( Scheme 42 ) [ 83 – 84 ].…”

Cobalt catalyzed sp3 C–H amination utilizing aryl azides

“…The direct amination of C–H bonds in a mild, functional group tolerant manner represents an important technology for the synthesis of biologically active molecules, including natural products and pharmaceutical agents. 1 Significant progress has been made in the development of catalysts capable of promoting metallonitrene initiated C–H amination utilizing carbamate, 2 – 6 sulfamate, 2 , 7 – 12 sulfonamide, 13 , 14 sulfamide, 15 – 18 and phosphoramide 19 reagents for both intra- and intermolecular C–H amination, and in some cases, useful levels of enantio-induction can also be achieved. 20 – 24 …”