Ethylene addition to Ru(CH2)(O)3 – A theoretical study

Quantum Chemical Study on Ethylene Addition to (O═)2Os(═NH)2and (O═)2Os(═NH)-cyclo-(−NHCH2CH2HN−) as Model Complexes for the Osmium-Catalyzed Aminohydroxylation of Olefins

“…This level of theory is the same as used in our work on the addition of RuO 4 to ethylene, 5b while the basis sets are slightly different from our other previous studies on ethylene addition to transition metal compounds. [7][8][9][10][11][12][13] Test calculations have shown that the level of theory in this work gives very similar results to those in our previous studies.…”

“…7,8 The [2þ2] pathway is finally favored over the [3þ2] addition for ReO 2 CH 2 CH 3 , 9 WOCH 2 (CH 3 ) 2 , MoOCH 2 (CH 3 ) 2 , and CrOCH 2 (CH 3 ) 2 . 10 For ethylene addition to TcO 2 CH 2 CH 3 , MnO 2 CH 2 CH 3 , 11 RuO 3 CH 2 , 12 IrO 2 CH 2 CH 3 , RhO 2 CH 2 -CH 3 , and CoO 2 CH 2 CH 3 , 13 the [3þ2] pathway is preferred over the [2þ2] alternative. Schrock reported the synthesis of RR 0 W(dNAr)(dCHC(CH 3 ) 3 ) and its reaction with ethylene, which yields RR 0 W(dNAr)(dCH 2 ) and H 2 CdCHC-(CH 3 ) 3 , which indicates that a [2þ2] reaction across the WdCHC(CH 3 ) 3 double bond occurred.…”

“…The situation changes when a metal−carbon double bond is involved: For OsO 3 CH 2 and OsO 2 (CH 2 ) 2 , the [2+2] cycloaddition across the MC double bond becomes competitive with the [3+2] pathway, although the latter reaction still has a lower activation barrier than the former. , The [2+2] pathway is finally favored over the [3+2] addition for ReO 2 CH 2 CH 3 , WOCH 2 (CH 3 ) 2 , MoOCH 2 (CH 3 ) 2 , and CrOCH 2 (CH 3 ) 2 . For ethylene addition to TcO 2 CH 2 CH 3 , MnO 2 CH 2 CH 3 , RuO 3 CH 2 , IrO 2 CH 2 CH 3 , RhO 2 CH 2 CH 3 , and CoO 2 CH 2 CH 3 , the [3+2] pathway is preferred over the [2+2] alternative. Schrock reported the synthesis of RR′W(NAr)(CHC(CH 3 ) 3 ) and its reaction with ethylene, which yields RR′W(NAr)(CH 2 ) and H 2 CCHC(CH 3 ) 3 , which indicates that a [2+2] reaction across the WCHC(CH 3 ) 3 double bond occurred .…”

Comparative theoretical study of [3+2] and [2+2] cycloadditions of ethylene and WXYMe2; X, Y=(O), (NH), (CH2)

“…As part of our ongoing theoretical work about the reaction mechanism of olefin addition to metal@E double bonds [3a,4a,b,5,7-13] we present a comparative study of [2+2] and [3+2] ethylene additions to W(@O) 2 (CH 3 ) 2 (W2), (O@)W(@NH)(CH 3 ) 2 (W3), (H 2 C@)W(@NH)(CH 3 ) 2 (W4), (H 2 C@) W(@CH 2 )(CH 3 ) 2 (W5) and (HN@)W(@NH)(CH 3 ) 2 (W6). We compare the results with our previously published data for the ethylene addition to (O@)W(@CH 2 )(CH 3 ) 2 (W1) [10a], its lighter homologs [10b], and similar group-7 [9,11], group-8 [7,8,12], and group-9 [13] compounds. Due to the diversity of the compounds, we only consider [3+2] and [2+2] pathways.…”

“…A different scenario is theoretically predicted when a metalcarbon double bond is involved: the [2+2] addition of ethylene across the M@C alkylidene bond becomes competitive with the [3+2] reaction for OsO 3 CH 2 and OsO 2 (CH 2 ) 2 [7,8] and the former reaction becomes favored over the latter for ReO 2 CH 3 CH 2 [9], WO(CH 3 ) 2 CH 2 , MoO(CH 3 ) 2 CH 2 , and CrO(CH 3 ) 2 CH 2 [10]. The [3+2] cycloaddition of ethylene is preferred for TcO 2 CH 3 CH 2 [11], RuO 3 CH 2 [12], IrO 2 CH 3 CH 2 , RhO 2 CH 3 CH 2 , and CoO 2 CH 3 CH 2 [13]. Experimentally, Schrock reported the synthesis of RR 0 W(@NAr) (@CHCMe 3 ) and he showed that the reaction of the latter with ethylene yields RR 0 W(@NAr)(@CH 2 ) and H 2 C@CHCMe 3 which indicates that a [2+2] addition across the W@CHCMe 3 double bond has taken place [14].…”