Novel Stable Chiral Ligation for Asymmetric Organoborane Conversions via 10-Substituted-9-borabicyclo[3.3.2]decanes

由稳定的重氮甲烷与b -甲氧基-9-硼代环[3.3.2]壬烷（B-MeO-9-BBN）反应制备了新的10-（取代）-9-硼代环[3.3.1]癸烷体系（BBDs）。这些试剂很容易以顺序方式分解，产生两种对映体纯形式的试剂。这些配合物与格氏试剂的反应直接提供b -烯丙基-、烯丙基-或丙炔- 10r - bbd，作为稳定的、可分离的对映体纯形式的化合物。相应的b -丁基（E和Z）和Z- γ - or -烯丙基试剂也很容易从对映体纯b - meo - 10r -9- bbd中制备。10-TMS和10-Ph试剂是专门为醛类和酮类的极端对映选择性添加而定制的。该项目的具体目标是利用这些强大的手性硼烷开发新的化学反应，包括1)与新型2-硼基-1,3-二烯的不对称“烯丙基硼化”，可能产生手性β -烯丙基甲醇；2)酮的不对称γ -甲氧基硼化，可能产生具有高非映对和对映选择性的Suzuki-Miyaura偶联和烯丙化，可能产生手性烯烯和β - tms同丙基醇。4) b -炔基bbd在烯酮和n-酰基上的共轭加成；5)酮类的不对称丙基硼化反应；6)1,1-二取代烯烃的不对称硼化反应得到适合不对称Suzuki-Miyaura烷基偶联的非外消旋产物。有机和大分子化学项目通过这一更新奖支持波多黎各大学化学系John A. Soderquist博士的研究。Soderquist教授和他的学生将研究含碳硼键化合物的合成和反应化学。这些新的“有机硼烷”试剂预计将等于或超过其他已知试剂或工艺报告的选择性，同时提供很大的通用性以及易于制备，处理和回收。这些研究利用有机硼烷的刚性、健壮的双环性质来创造一个稳定的“酶样”环境，以协调高度选择性和受控的反应。这种方法为研究、制药和化学工业中的各种合成应用提供了希望。

Novel 10-(substituted)-9-borabicyclo[3.3.2]decane systems (BBDs) are readily prepared from the reaction of stable diazomethanes with B-methoxy-9- borabicyclo[3.3.1]nonane (B-MeO-9-BBN). These reagents are easily resolved in a sequential manner producing both enantiomerically pure forms of the reagents. Reaction of these complexes with Grignard reagents directly provides B-allyl-, allenyl-, or propargyl-10R-BBDs, quantitatively, as stable, isolable compounds in enantiomerically pure form. The corresponding B-crotyl (E and Z) and Z-gamma-OR-allyl reagents are also readily prepared from the enantiomerically pure B-MeO-10R-9-BBDs. The 10-TMS and 10-Ph reagents are specifically tailored for extremely enantioselective additions to aldehydes and ketones, respectively. The specific goals of this project are to develop new chemistry with these robust chiral boranes, including 1) asymmetric "allylboration" with novel 2-boryl-1,3-dienes potentially leading to chiral beta-allenyl carbinols, 2) asymmetric gamma-methoxyallylboration of ketones with a fostriecin application, 3) asymmetric Suzuki-Miyaura coupling and allenylation potentially giving chiral allenes and beta-TMS homopropargylic alcohols with high diastereo- and enantioselectivity, 4) conjugate additions of B-alkynyl-BBDs to enones and N-acylimines, 5) asymmetric propargylboration of ketones, and 6) asymmetric hydroboration of 1,1-disubstituted alkenes to give non-racemic products which are suitable for asymmetric Suzuki-Miyaura alkyl coupling.With this renewal award, the Organic and Macromolecular Chemistry Program is supporting the research of Dr. John A. Soderquist of the Department of Chemistry at the University of Puerto Rico. Professor Soderquist and his students will study the synthesis and reaction chemistry of compounds containing bonds between carbon and boron. These new "organoborane" reagents are expected to equal or exceed the selectivities reported for other known reagents or processes while offering great versatility as well as ease of preparation, handling and recycling. These studies utilize the rigid, robust bicyclic nature of the organoboranes to create a stable, "enzyme-like" environment for orchestrating highly selective and controlled reactions. This methodology offers promise for a variety of synthetic applications in research and in the pharmaceutical and chemical industries.