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Preparation, Structure and Reactivity of 2‐Chloro‐, 2‐Fluoro‐ and 2‐Iodo‐2,3‐dihydro‐1 H ‐1,3,2‐diazaboroles
Author(s) -
Weber Lothar,
Dobbert Eckhard,
Boese Roland,
Kirchner Michael T.,
Bläser Dieter
Publication year - 1998
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/(sici)1099-0682(199808)1998:8<1145::aid-ejic1145>3.0.co;2-h
Subject(s) - chemistry , adduct , reactivity (psychology) , medicinal chemistry , redox , hexane , nuclear magnetic resonance spectroscopy , derivative (finance) , stereochemistry , proton nmr , organic chemistry , medicine , alternative medicine , pathology , financial economics , economics
A series of differently substituted 2‐chloro‐, 2‐fluoro‐ and 2‐iodo‐2,3‐dihydro‐1 H ‐1,3,2‐diazaboroles have been prepared by various methods. 1,3‐Di‐ tert ‐butyl‐2‐fluoro‐2,3‐dihydro‐1 H ‐1,3,2‐diazaborole ( 3a ), 1,3‐di‐ tert ‐butyl‐2‐chloro‐2,3‐dihydro‐1 H ‐1,3,2‐diazaborole ( 5a ), 1,3‐bis(2,6‐dimethyl‐phenyl)‐2‐chloro‐2,3‐dihydro‐1 H ‐1,3,2‐diazaborole ( 5b ), 2‐chloro‐4,5‐dimethyl‐1,3‐dineopentyl‐2,3‐dihydro‐1 H ‐1,3,2‐diazaborole ( 5c ), and 1,3‐di‐ tert ‐butyl‐2‐iodo‐2,3‐dihydro‐1 H ‐1,3,2‐diazaborole ( 6a ) were formed from the corresponding lithiated Z ‐1,2‐diaminoethenes, by treatment with BF 3 ·OEt 2 , BCl 3 , or BI 3 in n ‐hexane. Compounds 3a , 5a , and 5b are also available by sodium amalgam reduction of the adduct ( t Bu)(BF 3 )N=CH–CH=N(BF 3 )( t Bu) ( 2a ), and the borolium salts [RN a =CH–CH=N b (R)BCl 2 ]X (N a –B) ( 4a : R = t Bu, X = BCl 4 and 4b : R = 2,6‐Me 2 C 6 H 2 , X = Cl) respectively. The iodo derivative (2,6‐Me 2 C 6 H 2 )–N a –CH=CH–N b (2,6‐Me 2 C 6 H 2 )BI (N a –B) ( 6b ) was synthesized in a redox reaction between the 1,4‐diazabutadiene 1b and BI 3 . The novel compounds were characterized by 1 H‐, 11 B‐ and 13 C‐NMR spectroscopy, as well as by an X‐ray structure analysis of 6b .