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Synthesis and Reactivity of Monoborylacetylene Derivatives
Author(s) -
Gu Yiqun,
Pritzkow Hans,
Siebert Walter
Publication year - 2001
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 - 10.1002/1099-0682(200102)2001:2<373::aid-ejic373>3.0.co;2-6
Subject(s) - chemistry , hydroboration , adduct , catechol , reactivity (psychology) , medicinal chemistry , yield (engineering) , derivative (finance) , nuclear magnetic resonance spectroscopy , catalysis , organic chemistry , medicine , materials science , alternative medicine , pathology , economics , financial economics , metallurgy
The catechol‐substituted monoborylacetylenes 1a−d are obtained from the reaction of bis(diisopropylamino)borylacetylene with catechol derivatives and 2,2′‐biphenol. The catalytic trimerization of 1a−d with [(η 5 ‐C 5 H 5 )Co(CO) 2 ] yields isomeric mixtures of the triborylbenzene derivatives 2a,2a′ , 2b,2b′ , and 2c,2c′ . The reaction of 2a,2a′ with mesityllithium provides the hexamesityl‐substituted 1,3,5‐triborylbenzene 2e . Hydroboration of 1a with catecholborane affords a mixture of 1,1‐bis(1,3,2‐benzodioxaborol‐2‐yl)ethene ( 3a ) and trans ‐1,2‐bis(1,3,2‐benzodioxaborol‐2‐yl)ethene ( 4a ). Hydroboration of 1a and 3a with one or two mol of HBCl 2 and subsequent substitution of the chlorine atoms of the product with catechol leads in each case to the 1,1,1‐trisborylmethane derivative 5a in 83 and 78% yield, respectively, which forms the tris(THF) adduct 5a (thf) 3 . Treatment of 5a with t BuLi yields 1,1,1‐tris[di( tert ‐butyl)boryl]ethane 6a . [Co 2 (CO) 8 ] reacts with 1a to give 3‐(1,3,2‐benzodioxaborol‐2‐yl)‐1,2‐bis(tricarbonylcobalta)tetrahedrane (9a) . The new compounds have been characterized by NMR spectroscopy and mass spectrometry as well as by X‐ray structure analyses for 1a , 3a , 5a , 5a (thf) 3 , and 9a .