Intramolecular Donor-Assisted Cyclization of Organotin Compounds

✍ Scribed by Michael Mehring; Christian Löw; Markus Schürmann; Klaus Jurkschat

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 471 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/(sici)1099-0682(199905)1999:5<887::aid-ejic887>3.0.co;2-2

✦ Synopsis

New intramolecularly coordinated organotin compounds species under elimination of ethyl halide. Furthermore, the synthesis of [1(Sn),3(P)-Ph 2 SnOP(O)(OH)-5-tert-Bu-7-P(O)-containing the monoanionic O,C,O-coordinating ligand {4tert-Bu-2,6-[P(O)(OEt) 2 ] 2 C 6 H 2 } -have been synthesized by (OH) 2 ]C 6 H 2 (13) is described. Reaction of 8 with an excess of Me 3 SiBr leads to the unexpected formation of {2-substitution reactions starting from organotin halides. In view of the enhanced reactivity of the intramolecularly coor-[P(O)(OEt)(OSiMe 3 )]-4-tert-Bu-6-[P(O)(OEt) 2 ]C 6 H 2 }SnPhBr 2 (9) as a result of an O-Sn bond cleavage initiated by Me 3 SiBr dinated compounds {4-tert-Bu-2,6-[P(O)(OEt) 2 ] 2 C 6 H 2 }SnR 2 RЈ (2, R = Ph, RЈ = CH 2 SiMe 3 ; 3, R = RЈ = Ph; 6, R = RЈ = Cl), and subsequent reaction of the intermediate with further Me 3 SiBr under Sn-C bond cleavage. The high donor cationic tin species are suggested to occur as intermediates in the formation of the heterocyclic compounds [1(Sn),3(P)-capacity and the rigidity of the new ligand {4-tert-Bu-2,6-[P(O)(OEt) 2 ] 2 C 6 H 2 } -are demonstrated by X-ray diffraction Ph 2 SnOP(O)(OEt)-5-tert-Bu-7-P(O)(OEt) 2 ]C 6 H 2 (8), [1(Sn), 3(P)-Ph(Me 3 SiCH 2 )SnOP(O)(OEt)-5-tert-Bu-7-P(O)(OEt) 2 ]-analyses of the tetraorganotin compound 2 and the monoorganotin trichloride 6. Furthermore, the molecular C 6 H 2 (15), and {[1(Sn),3(P)-Cl 2 SnOP(O)(OEt)-5-tert-Bu-7-P(O)(OEt)]C 6 H 2 } 2 (16). The latter compounds are formed by structures of the 2,3,1-oxaphosphastannoles 8 and 16 are discussed. intramolecular cyclizations of pentacoordinate cationic tin

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