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1[ILLER, REZNICEK, ROWATT, AND LUNDBERG
Inorganic Chemistry CONTRIBUTION FROM THE CHEMISTRY DEPARTMEKT, DAKOTA, VERMILLIOK, SOUTH D.4KOTA 57069
UNIVERSITY O F SOUTH
Borane Cations with Functionally Substituted Bases BY S . E. MILLER,Ia D. L. REZNICEK,lb R. J. RO\17ATT,1cAND K. R. LUKDBERG*a
Received October 30, 1968 Monovalent and divalent borane cations derived from t-ivo amides, an amino acid ester, and several bases with group IV,
V, and VI organometallic substituents have been prepared and characterized. The hydrolytic stability eshibited by these boranes Fas a sensitive function of structure. Only the cations with dimethylformamide and ethyl S,S-dimethylglycinate had hydrolysis rates sufficiently rapid t o be measurable
Boron cation chemistry has developed rapidly after dimethylforniaiiiide (DMF) and N,N-dimethylacetaits late start with the elucidation of the structure of the mide (DAIAA)-and ethyl N,X-dimethylglycinate mere dianimoniate of diborane as HzB(SH3)z+BH4-.2 Now used t o prepare cation salts 1-7 in Table I. Without exception these salts mere crystalline white solids of there are many classes of these cations known: borane low melting points. cations: H2B(base)z+,3a H R B ( b a ~ e ) z + ,HzB(base) ~~ ( b a ~ e ’ ) + , ~H~ R , ~B ( b a s e ) ( b a ~ e ’ ) + , (base)BHzSCH,~~ A structural aspect of importance in the cations \Tith BHz(base)+,3d(ba~e)BHzSCH3BHzSCH3BHz(base)+;~~l DMF and DNA is the linkage to boron. Because of their “available” or unpaired electrons, either nitrogen disubstituted boron cations: RzB(base)z+;3b e--g and multivalent cations: B r B ( b a ~ e ) ~B~( tb, a~ ~ e ) ~ ~ + . ~or ~ oxygen in these amides can be the ligation site. The evidence favors bonding through the oxygen atoms New synthetic routes to cations h a w also been uncovered. Probably the most significant advance is the method of iodide displacement froin iodoboranes, pioneered by Douglass4 and modified t o an elegant method by Ryschlie.rvitsch5 (base)BHZI
+ base + (base)ZBHz+,I-
(1)
The borane class of cations is worth special attention because chemistry on intact cations x a s first denionstrated for them.3b Either or both of the hydrogen atoms bonded to boron may be replaced without significantly altering the remarkable kinetic stability of borane cations toward hydrolysis. A yet unexplored area is the chemistry of replacement or transformation of groups other than hydrogen on these species. This intriguing area is being studied here, and we wish to report a number of substituted borane cations with functionality on the base site.
Discussion Cations derived from bases with carbonyl functionality have been prepared by iodide displacement from amine iodoboranes, R 3 S B H z I . Two amides-K,S(1) (a! Author t o whom inquiries should be addressed at the University of South Dakota. (b) r a t i o n a l Science Foundation Trainee. (c) National Defense and Education Act Fellows. ( 2 ) ( a ) D . R. Schultz and R. W. Parry, J . Am. Chem. Soc., 80, 4 (1958:; (b) 8 . G. Shore and R . W , Parry, h i d . , 80, 8 1 2 , 1.5 (1938); ( c ) S.G. Shore, D. R. Girardot, and K. W.Parry, ibid.,80, 20 (1958). (3) The references listed are not exhaustive, rather representative citations of work on cation classes: (a) H. NOth and H. Reyer, Ber., 93, 1078, 2551 (1960); (b) N. E . Miller and E. L. Muetterties, J . Am. Chem. Soc.. 8 6 , 1033 (1964);(c) G. E. Ryschkewitsch and J. M. Garrett, i b i d . . 89, 5509 (1967): (d: R. J. Rowatt and II’. E. Rliller, ibid., 89, 5509 (1967); (e) J. Yi. Davidson and h l . French, C h e m Ind (London), 730 (1959); ( f ) S . Wiberg and J. W. Buchler, J. Am. Chem. Soc., 85;244 (1963); ( 9 ) R.&I. hlikhailov, et a/.. I z r . A k a d . S a u t S S S R , Ser. Khim., 2165 (1964); (h) C. W. Alakosky, G. I,. Galloway, and G. 1.2. Ryschkewitsch. Inoro. Ch,em.. 6, 1072 (1%;). ( 4 ) J. E. D o u g l a s , J . .4m. Cheni. SOC., 8 6 , 5431 (1964). ( 5 ) G. E. Ryschkemitsch, ibid., 89, 3145 (1967); I- data Douglass Synthesis.-Compounds 13, 14, and 17 in Table I are collcctcd in Table Ti. xere prepared by the method of D o ~ g l a s s . ~A typical preparation is given in detail below-. Data for the other t x o compounds are in Table 11. Acknowledgment.-Support of this work by a. grant Preparation of (CH3)3NBH2CH[Si(CH3),]As(CH3)3'.-The froin the Sational Science Foundation is sincerely ylide (CH,),AsCHSi(CH,), was prepared from 1.223 g ( 5 mmol) appreciated. of (CH3)3AsCH&(CH3),+,C1- and 2.90 ml ( 5 mmol) of n-butyl(11) C. W.RIakosky, G. L. Galloway, and C . E. Rysohke\+itsch, I n o i g . Chem., 6 , 1972 (1967).
(12) J E. Noll, J. L Speier, and B (1951)
r
Dsubert, J Ani Ciiein Soc 73, 38131
