Novel Catalytic Performance of Ruthenium Catalysts Toward the Characteristic Carbonylation Reactions

研制了一种新型钌催化体系[PPN][Ru_3H(CO)_<11>]/PCy_3[PPN=二（三苯基膦）-铝，Cy=环己基]，用于烯烃与甲酰胺和甲酸烷基酯的直接加氢酰胺化和加氢酯化反应。这些加成反应在氩气气氛下进行顺利，并且不需要一氧化碳来抑制甲酰基化合物的脱碳或维持催化活性。另一方面，在对钌催化的1,6 -炔分子间Pauson-Khand反应进行扩展的过程中，我们发现了新的（η^3-C_3H_5）RuBr(CO)_3/ et_3n催化的烯丙基碳酸酯与烯烃的羰基环化反应，得到了相应的高收率环戊烯酮。此外，钌催化环丁烯二酮与烯烃通过C-C键裂解偶联制备了环戊烯酮。例如，4-丁基-3-异丙氧基环丁-3-烯- 1,2 -二酮与2-降冰片烯在催化量为Ru_3(CO)_<12>和PEt_3的条件下，在160℃下，在3 atm的一氧化碳下，在THF中反应20 h，得到相应的环戊酮，4-丁基-5-异丙氧基三环[5.2.1.0^<2,6>]dec-4-en-3-one，收率为75% （exo 100%）。该反应通过环丁烯二酮和/或环丁烯二酮中间体进行，而环丁烯二酮中间体可通过活性钌催化剂使环丁烯二酮不对称开环而得到。总之，这两个反应将为钌催化羰基化反应开辟新的化学领域，并为环戊烯酮的制备提供新颖实用的方法。由于环戊烯酮在大量天然产物和生物活性化合物中具有广泛的丰度，环戊烯酮的制备非常有吸引力和重要性。这些环戊酮的合成可能是催化分子间Pauson-Khand反应的补充。

A novel ruthenium catalyst system of[PPN][Ru_3H(CO)_<11>]/PCy_3[PPN=bis(triphenylphosphine)-iminium, Cy=cyclohexyl]for the direct hydroamidation and hydroesterification of alkenes with formamides and alkyl formates has been developed. These addition reactions proceeded smoothly under an argon atmosphere, and carbon monoxide is not needed to suppress decarbonylation of formyl compounds or to maintain the catalytic activity.On the other hand, during our effort to extend the previously reported ruthenium-catalyzed intermolecular Pauson-Khand reaction of 1, 6-enynes, we have found novel(η^3-C_3H_5)RuBr(CO)_3/Et_3N-catalyzed carbonylative cyclization of allylic carbonates with alkenes to give the corresponding cyclopentenones in high yields. In addition, cyclopentenones were prepared by a novel rutheniumcatalyzed coupling of cyclobutenediones with alkenes via C-C bond cleavage. For example, treatment of 4-butyl-3-isopropoxycyclobut-3-ene-1, 2-dione with 2-norbornene in the presence of a catalytic amount of Ru_3(CO)_<12> and PEt_3 in THF under 3 atm of carbon monoxide at 160℃ for 20 h gave the corresponding cyclopentenone, 4-butyl-5-isopropoxytricyclo[5.2.1.0^<2,6>]dec-4-en-3-one, in 75% yield(exo 100%). The reaction proceeds via a ruthenacyclopentenedione and/or ruthenacyclobutenone intermediate, which would be obtained by unsymmetrical ring-opening of cyclobutenediones with an active ruthenium catalyst.In coclusion, both reactions will open up new chemistry in the field of ruthenium-catalyzed carbonylation reactions, and offer the novel and practical methods for preparation of cyclopentenones which are quite attractive and important due to the wide abundance of this structural unit in a large number of natural products and biologically active compounds. These cyclopentenone syntheses may be the complement of the catalytic intermolecular Pauson-Khand reaction.