Asymmetric retro-[1,4] Brook rearrangement and its stereochemical course at silicon
Asymmetric retro-[1,4] Brook rearrangement and its stereochemical course at silicon
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DOI：
10.1002/anie.200503734
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发表时间：
2006-01-01
影响因子：
16.6
通讯作者：
Tomooka, K
中科院分区：
文献类型：
--
作者：
Nakazaki, A;Nakai, T;Tomooka, K
2293 Angew。化学，2006,118,2293-2296 2006 Wiley-VCH Verlag GmbH & Co. KGaA， Weinheim硅烷在众多的变体中，烯丙氧基硅烷体系的重排是最吸引人的，因为由此产生的烯丙基硅烷具有很大的合成潜力除了正常的[1,2]移位，[1,4]移位在这个特定的系统中也是可能的[Eq.(1)]。然而，据我们所知，[1,4]重排导致g-烷氧基烯基硅烷体系仍然难以捉摸。在本文中，我们报道了一个简单的烯丙氧基硅烷的retro-[1,4] Brook重排，其中亲电试剂(E)、溶剂体系和迁移的硅基（R3Si）的明智选择实现了这种前所未有的[1,4]渗透性。特别值得注意的是该过程的立体专一性，通过使用具有硅立体中心的对映体纯烯丙氧基硅烷明确地确定了这一点[式(2)]。具有立体硅中心的g功能化烯丙基硅烷的不对称合成是通过这种逆-[1,4]布鲁克重排完成的。
2293 Angew. Chem. 2006, 118, 2293–2296 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim silanes.[1] Among numerous variants, the rearrangement of an allyloxysilane system is one of the most attractive because of the great synthetic potential of the resultant allylsilanes.[2] In addition to the normal [1, 2] shift, a [1, 4] shift is possible in this particular system [Eq.(1)]. To the best of our knowledge, however, the [1, 4] rearrangement leading to a g-alkoxyallylsilane system has remained elusive.[3]Herein, we report the retro-[1, 4] Brook rearrangement of a simple allyloxysilane, in which the judicious choice of electrophile (E), solvent system, and migrating silyl group (R3Si) enables this unprecedented [1, 4] periselectivity. Of particular note is the stereospecificity of this process, which has been unequivocally determined by using an enantiomerically pure allyloxysilane with a silicon stereocenter [Eq.(2)]. Asymmetric synthesis of g-functionalized allylsilanes with a stereogenic Si-center is accomplished with this retro-[1, 4] Brook rearrangement.