ChemInform Abstract: ASYMMETRICAL NONBRIDGEHEAD NITROGEN. XXVI. SYNTHESIS, CONFIGURATIONAL STABILITY, AND RESOLUTION OF N,N‐DIALKOXYAMINES INTO ANTIPODES

Abstract

Chlorierung der Alkoxyamine (I) mit tBuOCl liefert die N‐Chlor‐N‐alkoxyamine (II), die mit den Alkoholen (III) in Gegenwart von Et3N als Base [zur Synthese von (IVa) wird Na‐methylat als Base verwendet] unter nucleophiler Substitution zu den N,N‐Dialkoxyaminen (IV) reagieren; neben (IVd) bzw. (IVf) entstehen die Azoxy‐Verbindungen (Va) ( 12% Ausb.) bzw. (Vb) ( 26%).

Chiral ureas with two electronegative substituents at 1‐N: An unusual case of coexisting pyramidal and almost planar 1‐N atoms in the same crystal

“…3, Table 2). In conformation 7A the N(1) atom is strongly pyramidal (h N (2), O(4)À ÀN(1) 1.401 (2), O(1)À ÀC(1) 1.385 (2), O(2)À ÀC(1) 1.194 (2), O(3)À ÀC(2) 1.232 (2), O(4)À ÀC(3) 1.443 (2), N(1)À ÀC(2) 1.445 (2), N(2)À ÀC(2) 1.317(2), C(1)À ÀC(4) 1.494 (2); O(4)À ÀN(1)À ÀO (1) 108.68 (10), O(4)À ÀN(1)À ÀC(2) 111.70 (11), O(1)À ÀN(1)À ÀC (2) 111.75 (11), C(1)À ÀO(1)À ÀN(1) 114.5(1), N(1)À ÀO(4)À ÀC(3) 114.5(1), O(2)À ÀC(1)À ÀO(1) 123.3(1), O(2)À ÀC(1)À ÀC(4) 127.4(2), O(1)À ÀC(1)À ÀC(4) 109.3(1), O(3)À ÀC(2)À ÀN(2) 126.4(2), O(3)À ÀC(2)À ÀN(1) 118.0(1), N(2)À ÀC(2)À ÀN(1) 115.1 (1). [Color figure can be viewed in the online issue, which is available at www.interscience.…”

“…[1][2][3][4] The pyramidality of nitrogen in the OÀ ÀNÀ ÀX geminal system (X 5 OC(O)R, OAlk, N 1 C 5 H 5 , Cl) in Nacyloxy-N-alkoxycarbamates, 5 N-acyloxy-N-alkoxyureas, 5,6 N,N-dialkoxyureas, 6 N-alkoxy-N-(1-pyridinium)urea salts, 6 and N-chloro-N-alkoxyureas 7 has been established by XRD study of their structure.…”

“…The bonding of the nitrogen atom to two electronegative substituents possessing lone electron pairs (e.g., alkoxy groups in N,N-dialkoxy-N-tert-alkylamines 1 ) stabilizes pyramidality of the nitrogen atom and increases its inversion barrier. [1][2][3][4] The pyramidality of nitrogen in the OÀ ÀNÀ ÀX geminal system (X 5 OC(O)R, OAlk, N 1 C 5 H 5 , Cl) in Nacyloxy-N-alkoxycarbamates, 5 N-acyloxy-N-alkoxyureas, 5,6 N,N-dialkoxyureas, 6 N-alkoxy-N-(1-pyridinium)urea salts, 6 and N-chloro-N-alkoxyureas 7 has been established by XRD study of their structure.…”

“…(CH 2 Cl 2 À ÀC 6 H 14 ). 1 N-4-Chlorobenzoyloxy-N-ethoxyurea (8). 4-ClC 6 H 4 CO 2 Na (6.27 mmol, 6.27 g) and a solution of N-chloro-N-ethoxyurea 8 (3.12 mmol, 0.43 g) in MeCN (20 ml) were stirred at 208C for 43 h, then CH 2 Cl 2 (10 ml) was added.…”

“…(Me 2 CO-Et 2 O-C 6 H 14 ). 1 X-ray diffraction study of compounds 1, 5, 7, and 8 was performed at Xcalibur 3 diffractometer (graphite-monochromated MoK a CCD detector, x-scans). Structures were solved by direct methods and refined by full-matrix least squares procedure in anisotropic approximation for nonhydrogen atoms using SHELX-97 program package.…”