烯烃羰化—步制醇铑系催化新体系的研究

A New Catalysis System for One-Step Oxosynthesis of High Carbon Alcohol from Olefin

羰基铑催化剂由于其加氢性能较弱，在羰基化反应的研究中，通常仅作为烯烃氢甲酰化制醛的催化剂。产物中得不到醇。本文则报道了以Ｒｈ＿２（ＡｃＯ）＿４和Ｒｈ＿６（ＣＯ）＿１６为催化剂，在一个反应器内进行烯烃氢甲酰化，加氢制醇的研究。系统考察了Ｒｈ／Ｐｂｕ＿３／ＥｔＯＨ催化体系受各种反应条件的影响。在最佳反应条件下，烯烃转化率达１００％。对醇选择性亦在９９．５％以上，正异构比在２以上．为烯烃一步制醇建立了铑系催化新体系。文中并利用红外光谱测定了反应过程的催化剂物种．实验证明，由烯烃一步制醇是由烯烃首先进行氢甲酰化反应，然后由生成的醛进一步加氢成醇的一个串联反应过程。前一步骤反应速度较快，２ｈ内可使９５％以上的烯烃转化为醛，后面由醛加氢成醇则进行缓慢，在１００—１２０℃下，至少２２ｈ，才能使醛全部转化为醇。

Carbonyl rhodium catalysts were used only for hydroformylation of olefin to aldehydes in earlier workers'studies of carbonylation reactions because of their poor activity for hydrogenation. In this paper,oxosynthesis of alcohols from olefin by using Rh_2(AcO)_4,and Rh_6(CO)_16 as catalysts has been performed in an autoclave. The influence of various parameters on the reaction were studied with Rh/Pbu_3/EtOH as the catalytic system. A conversion of olefin is l00%and a selection of octanol yield is over 99.5% with a normal-to iso-alcohol ratio up to 2 under favourable reaction conditions.A onestep process of making alcohol products from olefin was established with rhodium catalysis system,The active species have been determined with IR in hydroformylation and hydrogenation. The reaction is a consecutive one.At first, aldehyde was formed via hydroformylation of olefin then alcohol via hydrogenation of aldehyde.The rate of the reaction is fast in the hydorformylation of 1-heptene.Olefin was converted by 95% to aldehyde in 2 h and the hydrogenation of aldehyde was very slow which took at least 22 h at 100-120℃ to get a conversion of 100%.