Revisiting the Phospha-Wittig-Horner Reaction
Revisiting the Phospha-Wittig-Horner Reaction
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DOI：
10.1021/om201158k
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发表时间：
2012-02-13
期刊：
影响因子：
2.8
通讯作者：
Ott, Sascha
中科院分区：
文献类型：
--
作者：
Arkhypchuk, Anna I.;Santoni, Marie-Pierre;Ott, Sascha
在Michaelis-Arbuzov条件下，P，P-二氯膦2a-c(RPCl2，R=Ph(A)，t-Bu(B)，2，4，6-Me3Ph(C))和P，P-二溴膦4d，e(RPBr2，R=(i-Pr)(3)SiCc(D)和H2C=CH(E))与亚磷酸三乙酯在Michaelis-Arbuzov条件下反应，生成定量产率的磷二膦3a-e。与W(CO)(5)络合，用CH3ONa处理后，得到多克量级的磷化Wittig-Horner试剂9a、b，总收率较高。在P-III(10d，e)上带有不饱和取代基的磷酸-Wittig-Horner试剂可以用类似的方法制备；然而，它们以一种不寻常的叶立德形式占优势，这种形式允许孤对分别与乙炔和乙烯基pi-体系之间发生共轭。用X-射线结晶学对磷酸盐9a进行了表征，结果表明它在几分钟内就能与丙酮顺利反应。根据反应条件的不同，生成的W(CO)(5)配位的磷杂烯可二聚成1，2-二亚磷酸或发生1，3-质子移动。此外，从W(CO)(5)配位的膦二膦酸酯5d，e开始的一锅法合成序列也被开发出来，以使化合物在磷酸-Wittig-Horner反应中与乙烯基和乙炔取代基接合。
P,P-Dichlorophosphines 2a-c (RPCl2, R = Ph (a), t-Bu (b), 2,4,6-Me3Ph (c)) and P,P-dibromophosphines 4d,e (RPBr2, R = (i-Pr)(3)SiC C (d) and H2C=CH (e)) react with triethylphosphite under Michaelis-Arbuzov conditions to give phosphinodiphosphonates 3a-e in quantitative yields. After complexation to W(CO)(5) and treatment with CH3ONa, phospha-Wittig-Horner reagents 9a,b are obtained on a multigram scale in good overall yield. Phospha-Wittig-Horner reagents with unsaturated, substituents at P-III (10d,e) can be prepared in analogous procedures; however, their prevail in an unusual ylide form that allows conjugation between the lone pair and the acetylene and vinyl pi-systems, respectively. Phosphinophosphonate 9a has been characterized by X-ray crystallography and is shown to react smoothly with acetone within minutes. The resulting W(CO)(5)-coordinated phosphaalkene is shown to dimerize to a 1,2-diphosphitane or to undergo a 1,3-proton shift depending on the reaction conditions. In addition, a one-pot synthetic sequence starting from W(CO)(5)-coordinated phosphinodiphosphonates 5d,e has been developed to engage compounds with vinyl and acetylene substituents in phospha-Wittig-Horner reactions.